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Cystic Fibrosis (CF)


Gregory Sawicki

, MD, MPH, Harvard Medical School

Reviewed/Revised Dec 2023
Topic Resources

Cystic fibrosis is a hereditary disease that causes certain glands to produce abnormally thick secretions, resulting in tissue and organ damage, especially in the lungs and the digestive tract.

  • Cystic fibrosis is caused by inherited abnormal genes changing the function of the cystic fibrosis protein leading to thick, sticky secretions to clog the lungs and other organs.

  • Typical symptoms include abdominal bloating, loose stools, and poor weight gain as well as coughing, wheezing, and frequent respiratory tract infections throughout life.

  • The diagnosis is based on sweat test results and/or genetic testing.

  • More than half of the people with this disease in the United States are adults.

  • Treatments include antibiotics, bronchodilators, medications to thin lung secretions, airway clearance treatments for respiratory problems, supplements of pancreatic enzymes and vitamins for digestive problems, and medications to improve the function of the cystic fibrosis protein in people with certain abnormal genes.

  • Some people benefit from liver and lung transplantation.

Cystic fibrosis is an inherited disease that leads to a shortened life span. In the United States, it occurs in about 1 of 3,300 White infants and in 1 of 15,300 Black infants. It is rare in people of Asian descent. There are approximately 40,000 people with cystic fibrosis living in the United States, and approximately 100,000 diagnosed with cystic fibrosis worldwide. Because improvements in treatment have extended life expectancy for people with cystic fibrosis, almost 60 percent of the people in the United States with this disease are adults. Cystic fibrosis is equally common among boys and girls.

Cystic Fibrosis: Not Just a Lung Disease

Cystic fibrosis affects the lungs and also several other organs.

In the lungs, thick bronchial secretions block the small airways, which become infected and inflamed. As the disease progresses, the bronchial walls thicken, the airways fill with infected secretions, areas of the lung contract, and lymph nodes enlarge.

In the liver, thick secretions block the bile ducts. Stones may develop in the gallbladder.

In the pancreas, thick secretions may block the gland completely so that digestive enzymes cannot reach the intestine. The pancreas may produce less insulin, so some people develop diabetes (usually in adolescence or adulthood).

In the small intestine, meconium ileus (a type of intestinal blockage) can result from thick secretions and may require surgery in newborns.

The reproductive organs are affected by cystic fibrosis in various ways, usually resulting in infertility in males.

The sweat glands in the skin secrete fluid containing more salt than normal.

Cystic Fibrosis: Not Just a Lung Disease

Causes of Cystic Fibrosis

Abnormal genes

Cystic fibrosis results when a person inherits two defective copies (variants) of a particular gene, one from each parent. This gene is called the cystic fibrosis transmembrane conductance regulator (CFTR). There are a number of variants of the CFTR gene. For example, the most common one is called the F508del variant. The CFTR gene controls the production of a protein that regulates the movement of chloride, bicarbonate, and sodium (salt) across cell membranes. Variants of the CFTR gene cause the protein to become dysfunctional. If the protein does not work correctly, the movement of chloride, bicarbonate, and sodium is disrupted, leading to thickening and increased stickiness of secretions throughout the body.

Worldwide, about 3 of 100 White people carry one defective copy of the CFTR gene. People with one defective copy are carriers, but they themselves do not get sick. About 3 of 10,000 White people inherit two defective copies of the gene and, as a result, develop cystic fibrosis.

Abnormal secretions

Cystic fibrosis affects many organs throughout the body and nearly all the glands that secrete fluids into a duct (exocrine glands).

The organs most commonly affected are the

  • Lungs

  • Pancreas

  • Intestines

  • Liver and gallbladder

  • Reproductive organs

The lungs are normal at birth, but problems can develop at any time afterward as thick secretions begin to block the small airways (mucus plugging). The plugging leads to chronic bacterial infections and inflammation that cause permanent damage to the airways (bronchiectasis Bronchiectasis Bronchiectasis is an irreversible widening (dilation) of portions of the breathing tubes or airways (bronchi) resulting from damage to the airway wall. The most common cause is severe or repeated... read more ). These problems make breathing increasingly difficult and reduce the lungs’ ability to transfer oxygen to the blood. People also may have frequent bacterial respiratory infections that affect the sinuses.

In the pancreas, blockage of ducts prevents digestive enzymes from reaching the small intestine. A lack of these enzymes leads to poor absorption of fats, proteins, and vitamins (malabsorption Overview of Malabsorption Malabsorption syndrome refers to a number of disorders in which nutrients from food are not absorbed properly in the small intestine. Certain disorders, infections, and surgical procedures can... read more ). This poor absorption, in turn, can lead to nutritional deficiencies and poor growth. Eventually, the pancreas can become scarred and no longer produce enough insulin, so some people develop diabetes Diabetes Mellitus (DM) in Children and Adolescents Diabetes mellitus is a disorder in which blood sugar (glucose) levels are abnormally high because the body does not produce enough insulin or fails to respond normally to the insulin produced... read more Diabetes Mellitus (DM) in Children and Adolescents . However, a small percentage of people who have cystic fibrosis and carry certain variants do not develop pancreatic digestive problems.

The intestines can become blocked by thick secretions. This blockage is common immediately after birth because the contents of the fetus's digestive tract (called meconium) are abnormally thick. Such blockage in the small intestine is called meconium ileus Meconium Ileus Meconium ileus is blockage of the small intestine in a newborn caused by excessively thick intestinal contents (meconium), usually as a result of cystic fibrosis. Meconium ileus usually results... read more and in the large intestine is called meconium plug syndrome Meconium Plug Syndrome Meconium plug syndrome is blockage of the large intestine with thick intestinal contents (meconium). Meconium plug syndrome may result from Hirschsprung disease or cystic fibrosis. Typically... read more . Older children and adults may also have problems with constipation and blockage of the intestines (distal intestinal obstruction syndrome).

The reproductive organs can be blocked by thick secretions, which can cause infertility. Almost all men are infertile, but infertility is much less common in women.

The sweat glands secrete fluid containing more salt than normal, increasing the risk of dehydration.

Symptoms of Cystic Fibrosis

The symptoms of cystic fibrosis can vary depending on a person's age.

Newborns and young children

The first symptom of cystic fibrosis in an infant who does not have meconium ileus is often a delay in regaining birth weight or poor weight gain at 4 to 6 weeks of age. This poor weight gain is due to poor absorption of nutrients related to inadequate amounts of pancreatic enzymes. The infant has frequent, bulky, foul-smelling, oily stools and may have a bloated (distended) abdomen. Without treatment, weight gain is slow despite a normal or large appetite.

Older children and adults

Unless a diagnosis is made through newborn screening, about half the children with cystic fibrosis are first taken to the doctor because of frequent coughing, wheezing, and respiratory tract infections. Coughing, the most noticeable symptom, is often accompanied by gagging, vomiting, and disturbed sleep. Children may have difficulty breathing, wheezing, or both. As the disease progresses, children develop a declining tolerance for exercise, lung infections tend to occur more frequently, the chest becomes barrel-shaped, and insufficient oxygen may make the fingers clubbed (see Clubbing Clubbing Clubbing is enlargement of the tips of the fingers or toes and a change in the angle where the nails emerge. Clubbing occurs when the amount of soft tissue beneath the nail beds increases. It... read more Clubbing ) and the nail beds bluish. Polyps may form in the nose. The sinuses may fill with thick secretions, leading to chronic or recurring sinus infections.

Older children and adults may have episodes of constipation or develop recurring and sometimes chronic blockage of the intestines. Symptoms include a change in stooling pattern, crampy abdominal pain, a decreased appetite, and sometimes vomiting. Gastroesophageal reflux Gastroesophageal Reflux Disease (GERD) In gastroesophageal reflux disease, stomach contents, including acid and bile, flow backward from the stomach into the esophagus, causing inflammation in the esophagus and pain in the bottom... read more Gastroesophageal Reflux Disease (GERD) is relatively common among children and adults.

When a child or adult with cystic fibrosis sweats excessively in hot weather or because of a fever, dehydration may result because of the increased loss of salt and water. Parents may notice the formation of salt crystals or even a salty taste on their child’s skin.

As the disease progresses, lung infection becomes a major concern. Recurring lung infections gradually destroy the lungs.

Complications of Cystic Fibrosis

There are many complications of cystic fibrosis.

Inadequate absorption of the fat-soluble vitamins A, D, E, and K may lead to night blindness, osteopenia (decrease in bone density), osteoporosis Osteoporosis Osteoporosis is a condition in which a decrease in the density of bones weakens the bones, making breaks (fractures) likely. Aging, estrogen deficiency, low vitamin D or calcium intake, and... read more Osteoporosis , anemia Overview of Anemia Anemia is a condition in which the number of red blood cells is low. Red blood cells contain hemoglobin, a protein that enables them to carry oxygen from the lungs and deliver it to all parts... read more , and bleeding disorders. In untreated infants and toddlers, the lining of the rectum may protrude through the anus, a condition called rectal prolapse Rectal Prolapse Rectal prolapse is a painless protrusion of the rectum through the anus. A rectal prolapse is often triggered while straining, such as during a bowel movement. The diagnosis is based on an examination... read more Rectal Prolapse . Infrequently, infants with cystic fibrosis who have been fed soy formula or hypoallergenic formula may develop anemia and swelling of the extremities, because they are not absorbing enough protein.

Complications of cystic fibrosis in adolescents and adults include rupture of the small air sacs of the lung (alveoli) into the pleural space (the space between the lung and chest wall). This rupture can allow air to enter into the pleural space (pneumothorax Pneumothorax A pneumothorax is partial or complete collapse of the lung due to the presence of air between the two layers of pleura (thin, transparent, two-layered membrane that covers the lungs and also... read more Pneumothorax ), which collapses the lung. Other complications include heart failure Heart Failure (HF) Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more Heart Failure (HF) and massive or recurring bleeding in the airways.

About 2% of children, 20% of adolescents, and up to 50% of adults with cystic fibrosis develop diabetes Diabetes Mellitus (DM) Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Symptoms of diabetes may... read more for which they must take insulin because the scarred pancreas can no longer produce enough insulin.

In almost all people with cystic fibrosis, the gallbladder is small, filled with thick bile, and does not function well. About 10% of people develop gallstones Gallstones Gallstones are collections of solid material (predominantly crystals of cholesterol) in the gallbladder. The liver can secrete too much cholesterol, which is carried with bile to the gallbladder... read more , but only a small percentage develops symptoms. Surgical removal of the gallbladder is rarely needed.

People with cystic fibrosis often have impaired reproductive function. Almost all men have a low or absent sperm count (which makes them sterile) because one of the ducts of the testis (the vas deferens) has developed abnormally and blocks the passage of sperm. In women, cervical secretions are too thick, causing somewhat decreased fertility. However, many women with cystic fibrosis have carried pregnancies to term. The outcome of the pregnancy for both the mother and the newborn is related to the mother's health status during pregnancy. Otherwise, sexual function is not impaired in men or women.

Other complications may include arthritis, chronic pain, problems sleeping and obstructive sleep apnea Obstructive sleep apnea Sleep apnea is a serious disorder in which breathing repeatedly stops long enough to disrupt sleep and often temporarily decrease the amount of oxygen and increase the amount of carbon dioxide... read more Obstructive sleep apnea , kidney stones Stones in the Urinary Tract Stones (calculi) are hard masses that form in the urinary tract and may cause pain, bleeding, or an infection or block of the flow of urine. Tiny stones may cause no symptoms, but larger stones... read more Stones in the Urinary Tract , kidney disease, depression Depression Depression is a feeling of sadness and/or a decreased interest or pleasure in activities that becomes a disorder when it is intense enough to interfere with functioning. It may follow a recent... read more and anxiety Overview of Anxiety Disorders Anxiety is a feeling of nervousness, worry, or unease that is a normal human experience. It is also present in a wide range of mental health conditions, including generalized anxiety disorder... read more , sensorineural hearing loss Hearing Loss Worldwide, about half a billion people (almost 8% of the world's population) have hearing loss. More than 15% of people in the United States have some degree of hearing loss that affects their... read more Hearing Loss and ear ringing Ear Ringing or Buzzing Ringing in the ears (tinnitus) is noise originating in the ear rather than in the environment. It is a symptom and not a specific disease. Tinnitus is very common—10 to 15% of people experience... read more (tinnitus) caused by exposure to medications that damage the ears Ear Disorders Caused by Drugs Many drugs, including medications, can damage the ears. These drugs are called ototoxic drugs. They include the antibiotics streptomycin, tobramycin, gentamicin, neomycin, and vancomycin, as... read more (especially aminoglycosides Aminoglycosides Aminoglycosides are a class of antibiotics used to treat serious bacterial infections, such as those caused by gram-negative bacteria (especially Pseudomonas aeruginosa). Aminoglycosides... read more ), chronic sinus infections Chronic sinusitis Sinusitis is inflammation of the sinuses, most commonly caused by a viral or bacterial infection or by an allergy. Some of the most common symptoms of sinusitis are pain, tenderness, nasal congestion... read more , and an increased risk of cancer of the bile ducts Tumors of the Bile Ducts and Gallbladder Tumors, both noncancerous and cancerous, within the bile ducts or gallbladder are rare. Ultrasonography or MRI/MRCP can usually detect a tumor in the bile ducts or gallbladder. These cancers... read more Tumors of the Bile Ducts and Gallbladder , pancreas Pancreatic Cancer Smoking, chronic pancreatitis, obesity, and exposure to certain chemicals are risk factors for pancreatic cancer. Abdominal pain, weight loss, jaundice, and vomiting are some typical symptoms... read more , and intestines Colorectal Cancer Family history and some dietary factors (low fiber, high fat) increase a person’s risk of colorectal cancer. Typical symptoms include bleeding during a bowel movement, fatigue, and weakness... read more Colorectal Cancer .

Diagnosis of Cystic Fibrosis

  • Newborn screening test

  • Sweat test

  • Genetic testing

  • Carrier screening

  • Other tests

Newborn screening

Screening tests for cystic fibrosis are done on all newborns in the United States. A drop of blood is collected on a piece of filter paper and the level of trypsin (a digestive enzyme from the pancreas) is measured. If the trypsin level in the blood is high, newborns undergo confirmatory testing, which includes sweat testing and/or genetic testing. Most cases of cystic fibrosis are now identified by newborn screening tests.

If newborn screening was not done, the diagnosis of cystic fibrosis is usually confirmed in infancy or early childhood, but cystic fibrosis goes undetected until adolescence or early adulthood in about 10% of people with the disease.

Sweat test

A sweat test is done in newborns who have a positive newborn screening test and in infants, children, and adults who have symptoms that suggest cystic fibrosis. This test, which is done on an outpatient basis, measures the amount of salt in sweat. The drug pilocarpine is placed on the skin to stimulate sweating, and filter paper or thin tubing is placed against the skin to collect the sweat. The concentration of salt in the sweat is then measured. A salt concentration higher than normal confirms the diagnosis of cystic fibrosis in people who have symptoms of cystic fibrosis or who have a sibling with cystic fibrosis. Although the results of this test are valid any time after a newborn is 48 hours old, collecting a large enough sweat sample from a newborn younger than about 2 weeks old may be difficult.

Genetic testing

Genetic testing for an abnormal CFTR gene can help diagnose cystic fibrosis in a newborn who has a positive newborn screening test result, in a person who shows one or more typical symptoms, or in a person who has a sibling with cystic fibrosis. Finding 2 abnormal cystic fibrosis genes (variants) is consistent with the diagnosis of cystic fibrosis. However, a positive sweat test is still needed to confirm the diagnosis. In addition, because typical genetic testing does not look for all of the more than 2,000 different cystic fibrosis variants, failure to detect 2 variants does not guarantee the person does not have cystic fibrosis (although the chance of having cystic fibrosis is very low). The disease can be diagnosed prenatally by doing genetic testing on the fetus using chorionic villus sampling Chorionic Villus Sampling Prenatal testing for genetic disorders and birth defects involves testing a pregnant woman or fetus before birth (prenatally) to determine whether the fetus has certain abnormalities, including... read more or amniocentesis Amniocentesis Prenatal testing for genetic disorders and birth defects involves testing a pregnant woman or fetus before birth (prenatally) to determine whether the fetus has certain abnormalities, including... read more .

Some infants with a positive newborn screening test for cystic fibrosis can be hard to classify, even after sweat testing and genetic testing. These are infants who have no cystic fibrosis–related symptoms, sweat test results that are in-between the positive and negative ranges, and either no or only one cystic fibrosis gene variant. Doctors diagnose this group as having CFTR-related metabolic syndrome (CRMS), also called cystic fibrosis screen positive, inconclusive diagnosis (CFSPID). Although most of these infants remain healthy, later in life about 10% develop symptoms related to cystic fibrosis and are diagnosed with cystic fibrosis or a cystic fibrosis–related disorder. Thus, all of these children should be monitored regularly in a cystic fibrosis care center.

Some people, usually adults, develop symptoms that affect only one organ, often with an intermediate sweat test result and without 2 cystic fibrosis–causing variants. For example, symptoms may affect only the pancreas (resulting in pancreatitis Overview of Pancreatitis Pancreatitis is inflammation of the pancreas. The pancreas is a leaf-shaped organ about 5 inches (about 13 centimeters) long. It is surrounded by the lower edge of the stomach and the first... read more ), the lungs (resulting in bronchiectasis Bronchiectasis Bronchiectasis is an irreversible widening (dilation) of portions of the breathing tubes or airways (bronchi) resulting from damage to the airway wall. The most common cause is severe or repeated... read more ), or the male reproductive organs (resulting in infertility). They are diagnosed with a CFTR-related disorder.

Carrier testing

Carrier testing Genetic Carrier Screening Genetic disorders are caused by abnormalities in one or more genes or chromosomes. Some genetic disorders are hereditary and others are spontaneous. Hereditary genetic disorders are passed down... read more can be done for people who want to become parents or are looking for prenatal care. In particular, relatives of a person with cystic fibrosis may want to know whether they are at increased risk of having children with the disease, and they should be offered genetic testing and counseling. A blood sample is taken to help determine whether a person has a defective cystic fibrosis gene (variant).

Unless both potential parents have at least one such variant, their children will not have cystic fibrosis. If both parents carry a defective cystic fibrosis gene, each pregnancy has a 25% chance of producing a child with cystic fibrosis, a 50% chance of producing a child who is a carrier, and a 25% chance of producing a child with no defective cystic fibrosis genes.

Other tests

Because cystic fibrosis can affect several organs, other tests may be helpful. Pancreatic enzyme levels are usually reduced, and an analysis of the person’s stool may reveal low or undetectable levels of the digestive enzyme elastase (secreted by the pancreas) and high levels of fat.

Blood tests are done to determine whether insulin secretion is reduced and blood sugar levels are high. Blood tests are also done to look for problems with the liver and to measure fat-soluble vitamin levels.

Doctors routinely take samples of material from the throat or coughed up from the lungs and culture it to identify bacteria in the airways and help them decide which antibiotics may be needed.

Pulmonary function tests Pulmonary Function Testing (PFT) Pulmonary function tests measure the lungs' capacity to hold air, to move air in and out, and to absorb oxygen. Pulmonary function tests are better at detecting the general type and severity... read more Pulmonary Function Testing (PFT) may show that breathing is compromised and are good indicators of how well the lungs are functioning. These tests are done several times a year and whenever there is a decline in a person's health.

Treatment of Cystic Fibrosis

  • Routine immunizations

  • Antibiotics, inhaled drugs to thin airway secretions, and airway clearance techniques to remove airway secretions

  • Medications that help prevent airways from narrowing (bronchodilators) and sometimes corticosteroids

  • Pancreatic enzyme and vitamin supplements

  • High-calorie diet

  • In people with specific variants, CFTR modulators

A person with cystic fibrosis should have a comprehensive program of therapy directed by a doctor experienced with cystic fibrosis care—usually a pediatrician or an internist—along with a team of other doctors, nurses, a dietitian, a respiratory or physical therapist, and ideally a social worker, genetics counselor, pharmacist, and a mental health professional. The goals of therapy include long-term prevention and treatment of lung and digestive problems and other complications, maintenance of good nutrition, and encouragement of physical activity.

Children with cystic fibrosis need mental health and social support because they may be unable to participate in normal childhood activities and may feel isolated. Much of the burden of treating a child with cystic fibrosis falls on the parents, who should receive adequate information, training, and support so they can understand the disorder and the reasons for the treatments.

Adolescents need guidance and education as they transition to independence and assume responsibility for their care.

Adults need support as they deal with issues related to employment, relationships, health insurance, and deteriorating health.

Treatments for the lungs

The treatment of lung problems is focused on

  • Preventing airway blockage

  • Controlling infection

The person should receive all routine immunizations Childhood Vaccination Schedules Vaccination protects children against many infectious diseases. Vaccines contain either noninfectious components of bacteria or viruses or whole forms of these organisms that have been weakened... read more , particularly for infections that can cause respiratory problems such as Haemophilus influenzae Haemophilus influenzae Type b Vaccine The Haemophilus influenzae type b (Hib) vaccine helps protect against bacterial infections due to Hib, such as pneumonia and meningitis. These infections may be serious in children. Use... read more , influenza Influenza Vaccine The influenza virus vaccine helps protect against influenza. Two types of influenza virus, type A and type B, regularly cause seasonal epidemics of influenza in the United States. There are... read more , measles Measles, Mumps, and Rubella Vaccine The measles, mumps, and rubella (MMR) vaccine is a combination vaccine that helps protect against these three serious viral infections. The vaccine contains live but weakened measles, mumps... read more , pertussis Diphtheria-Tetanus-Pertussis Vaccine The diphtheria, tetanus, and pertussis vaccine is a combination vaccine that protects against these three diseases: Diphtheria usually causes inflammation of the throat and mucous membranes... read more , pneumococcus Pneumococcal Vaccine Pneumococcal vaccines help protect against bacterial infections caused by Streptococcus pneumoniae (pneumococci). Pneumococcal infections include ear infections, sinusitis, pneumonia... read more , varicella Varicella Vaccine The varicella vaccine helps protect against chickenpox (varicella), a very contagious infection caused by the varicella-zoster virus. It causes an itchy rash that looks like small blisters with... read more , and COVID-19 COVID-19 Vaccine Coronavirus disease 2019 (COVID-19) vaccines provide protection against COVID-19. COVID-19 is the disease caused by infection with the SARS-CoV-2 virus. There are multiple COVID-19 vaccines... read more .

Airway clearance techniques, which include postural drainage, chest percussion, hand vibration over the chest wall, and encouragement of coughing (see Chest Physical Therapy Chest Physical Therapy Chest physical therapy uses mechanical techniques, such as chest percussion, postural drainage, and vibration, to help clear secretions from the lungs. Respiratory therapists use several different... read more Chest Physical Therapy ), are started when cystic fibrosis is first diagnosed. Parents of a young child can learn these techniques and carry them out at home every day. Older children and adults can carry out airway clearance techniques independently by using special breathing devices, an inflatable vest that vibrates at a high frequency (a high-frequency oscillation vest), or special breathing maneuvers. Aerobic exercise, done regularly, can also help keep the airways clear.

Bronchodilators are medications that help prevent the airways from narrowing. People usually take bronchodilators by inhaling them. People with severe lung problems and a low level of oxygen in the blood may need supplemental oxygen therapy. In general, people with chronic respiratory failure do not benefit from using a ventilator (breathing machine). However, occasional, short periods of mechanical ventilation in the hospital may help during an acute infection, after a surgical procedure, or while waiting for a lung transplant.

Medications that help thin the thick mucus in the airways, such as dornase alfa or hypertonic saline (a highly concentrated salt solution), are widely used. These medications are inhaled through a nebulizer. They make it easier to cough up sputum, improve lung function, and may also decrease the frequency of serious respiratory tract infections.

Corticosteroids, such as prednisone or dexamethasone, given by mouth can relieve symptoms in infants with severe bronchial inflammation, in people who have narrowed airways that cannot be opened with bronchodilators, and in people who have an allergic lung reaction to a type of fungus (allergic bronchopulmonary aspergillosis Allergic Bronchopulmonary Aspergillosis Allergic bronchopulmonary aspergillosis is an allergic lung reaction to a type of fungus (most commonly Aspergillus fumigatus) that occurs in some people with asthma or cystic fibrosis... read more ). Allergic bronchopulmonary aspergillosis is also treated with an antifungal medication given by mouth, by vein, or both.


Antibiotics are often used to treat both acute and chronic respiratory tract infections in people with cystic fibrosis. A sample of coughed-up sputum or a swab of a sample from the back of the throat and tonsils is collected and tested at regular intervals during stable health, and also during periods of increasing symptoms, so that the infecting organism can be identified and the doctor can choose the medications most likely to control it. Staphylococcus aureus, including methicillin-resistant or methicillin-sensitive strains, and Pseudomonas species are commonly found. Many different antibiotics can be given by mouth to treat staphylococcal infections. To treat a new Pseudomonas infection, people are given the inhaled form of tobramycin, aztreonam, or colistin for 4 weeks.

However, if the infection is severe, or results in significant worsening of symptoms or lung function, antibiotics given by vein (intravenously) may be needed. For this treatment, the aminoglycoside Aminoglycosides Aminoglycosides are a class of antibiotics used to treat serious bacterial infections, such as those caused by gram-negative bacteria (especially Pseudomonas aeruginosa). Aminoglycosides... read more tobramycin (or sometimes amikacin) is combined with another antibiotic that specifically targets Pseudomonas. These other antibiotics include cephalosporins Cephalosporins Cephalosporins are a subclass of antibiotics called beta-lactam antibiotics (antibiotics that have a chemical structure called a beta-lactam ring). Beta-lactam antibiotics also include carbapenems... read more , penicillins Penicillins Penicillins are a subclass of antibiotics called beta-lactam antibiotics (antibiotics that have a chemical structure called a beta-lactam ring). Carbapenems, cephalosporins, and monobactams... read more , fluoroquinolones Fluoroquinolones Fluoroquinolones are a class of broad-spectrum antibiotics that are used to treat a variety of infections. Fluoroquinolones include the following: Ciprofloxacin Delafloxacin Gemifloxacin read more , and monobactams Aztreonam Aztreonam is the only antibiotic in an antibiotic class called monobactams, which are a subclass of beta-lactam antibiotics (antibiotics that have a chemical structure called a beta-lactam ring)... read more . This treatment often requires hospitalization, but part of the treatment may be given at home.

Taking the inhaled form of tobramycin or aztreonam every other month for a long time and also continuously taking an oral form of the antibiotic azithromycin 3 times each week may help control chronic Pseudomonas infection and slow the decline in lung function.

CFTR modulators

CFTR modulators are oral medications taken chronically that improve the function of the defective protein made by variants in the CFTR gene.

There are 4 CFTR modulators or combinations for people who have specific variants: ivacaftor, lumacaftor/ivacaftor, tezacaftor/ivacaftor, and elexacaftor/tezacaftor/ivacaftor. These medications can be used to treat about 90% of people who have cystic fibrosis. Doctors give these medications to people based on their age and the variants they have.

Ivacaftor can be given to people 1 month of age and older who have at least 1 copy of a specific cystic fibrosis variant.

The combination of lumacaftor and ivacaftor can be given to people 1 years of age and older who carry 2 copies of the F508del variant.

The combination of tezacaftor and ivacaftor can be given to people 6 years of age and older who carry 2 copies of the F508del variant or other specified variants.

The combination of elexacaftor, tezacaftor, and ivacaftor can be given to people 2 years of age and older who carry at least 1 copy of the F508del variant or 1 copy of certain rare variants.

CFTR modulators can improve lung function, pancreas function, and quality of life; increase weight; and decrease the salt concentration in sweat and the frequency of lung infections and hospitalizations. Although all of these drugs can be helpful, only ivacaftor and the combination of elexacaftor, tezacaftor, and ivacaftor are considered to be highly effective therapy.

Doctors are working to develop drugs that will help people with other variants that cause cystic fibrosis.

Enemas and stool softeners

Diet and supplements

The diet should provide enough calories and protein for normal growth. Because digestion and absorption can be abnormal even when pancreatic enzyme supplements are used, most children need to consume 30 to 50% more calories than the usually recommended amount to ensure adequate growth. The proportion of fat should be normal to high. High-calorie oral supplements can provide extra calories for children and adults.

Medications that stimulate the appetite may be helpful (although many people with cystic fibrosis have a strong appetite without any such medications). When people exercise, have a fever, or are exposed to hot weather, they should increase their fluid and salt intake.

Pancreatic enzyme supplements

People whose pancreas has been affected by cystic fibrosis must take capsules of pancreatic enzyme supplements with all meals and snacks. For infants, parents open the capsules and mix the contents with an acidic food such as applesauce so that the special coating on the pancreatic enzyme supplement does not dissolve before reaching the intestines. For some people, medications that reduce stomach acid Medications for the Treatment of Stomach Acid Stomach acid plays a role in a number of disorders of the stomach, including peptic ulcer, gastritis, and gastroesophageal reflux disease (GERD). Although the amount of acid present in the stomach... read more , such as a histamine-2 blocker or a proton pump inhibitor, can improve the effectiveness of the pancreatic enzymes. Special milk formulas containing protein and fats that are easy to digest may help infants who have pancreatic problems and poor growth.


In addition to insulin, management includes nutrition counseling, a diabetes self-management program, and monitoring for eye and kidney complications. People also need special nutrition counseling because standard dietary recommendations for people with only diabetes or only cystic fibrosis are not adequate.


At times, surgery may be needed to treat a collapsed lung, chronic sinus infections, severe chronic infection restricted to one area of the lung, bleeding from blood vessels in the esophagus, gallbladder disease, or obstruction of the intestine. Massive or recurring bleeding in the lung can be treated by a procedure called embolization, which blocks off the bleeding artery.

Double lung transplantation Lung and Heart-Lung Transplantation Lung transplantation is the surgical removal of a healthy lung or part of a lung from a living person and then its transfer into someone whose lungs no longer function. Heart-lung transplantation... read more for severe lung disease is becoming more routine and more successful with experience and improved techniques. For adults who have cystic fibrosis, average survival after a double lung transplant is about 9 years.

Other treatments

Medications to treat chronic inflammation of the sinuses (sinusitis) are needed because this problem is very common. Treatment options include flushing a saltwater solution through the nose (nasal saline irrigation), inhaling dornase alfa into the nose using a nebulizer, and irrigating the nose and sinuses with antibiotics. A corticosteroid nasal spray is recommended to treat inflammation and swelling of the mucous membranes of the nose (allergic rhinitis).

People who have heart failure Heart Failure (HF) Heart failure is a disorder in which the heart is unable to keep up with the demands of the body, leading to reduced blood flow, back-up (congestion) of blood in the veins and lungs, and/or... read more Heart Failure (HF) are given medications (diuretics) to reduce the amount of fluid they retain. Diuretics help by increasing the amount of water the kidneys can get rid of from the body. People should also limit their intake of table salt and salty foods.

Injections of human growth hormone may improve lung function, increase height and weight, and reduce the rate of hospitalization. However, this medication is costly and inconvenient for people to receive, so doctors do not commonly prescribe it.

Some people with low oxygen levels in their blood may need supplemental oxygen that is usually given through a two-pronged nasal tube (cannula). Some people are treated with a tight-fitting mask placed over the nose or nose and mouth. A mixture of oxygen and air is delivered under pressure through the mask. This technique, called bilevel positive airway pressure Alternatives Mechanical ventilation is use of a machine to aid the movement of air into and out of the lungs. Some people with respiratory failure need a mechanical ventilator (a machine that helps air get... read more (BiPAP) or continuous positive airway pressure Obstructive sleep apnea Sleep apnea is a serious disorder in which breathing repeatedly stops long enough to disrupt sleep and often temporarily decrease the amount of oxygen and increase the amount of carbon dioxide... read more Obstructive sleep apnea (CPAP), can help people maintain normal oxygen levels while they sleep.

End-of-life issues

People who have cystic fibrosis and their family members need to have discussions with their doctor and care team about their prognosis and what types of treatment they want to receive. These discussions are especially important for people whose lung function is worsening. People need to be prepared for what is to come and know what treatments may be done to extend life. With advanced cystic fibrosis, people and their families need to discuss the potential benefits and burdens of lung transplantation.

Doctors should give people who have cystic fibrosis the information they need to make care choices and should help people determine how and when to accept dying and how to talk about dying.

When aggressive treatments are no longer helpful, doctors may begin giving people treatments that aim only to relieve symptoms (called palliative care Hospice Care Hospice is a concept and a program of care that is specifically designed to minimize suffering for dying people and their family members. In the United States, hospice is the only widely available... read more ). People usually do best when they make such decisions for end-of-life care well in advance of needing to. Such early discussions are very important because, later on, the illness often prevents people from explaining their wishes. This process of making decisions in advance for end-of-life care is called advance care planning Advance Directives Health care advance directives are legal documents that communicate a person’s wishes about health care decisions in the event the person becomes incapable of making health care decisions. There... read more . Such planning should involve the execution of appropriate legal documents that reflect the person's wishes regarding end-of-life care.

Prognosis for Cystic Fibrosis

The severity of cystic fibrosis varies greatly from person to person regardless of age. The severity is determined largely by how much the lungs are affected. In the United States, people with cystic fibrosis who were born in the year 2021 are predicted to live to about 65 years of age. The outlook for longer survival has improved steadily as people are diagnosed earlier and treatments can now postpone some of the changes that occur in the lungs. Long-term survival is significantly better in people who do not develop pancreatic problems.

However, deterioration is inevitable, leading to loss of lung function and eventually death. People with cystic fibrosis usually die of respiratory failure Respiratory Failure Respiratory failure is a condition in which the level of oxygen in the blood becomes dangerously low or the level of carbon dioxide in the blood becomes dangerously high. Conditions that block... read more after many years of deteriorating lung function. A small number, however, die of heart failure, liver disease, bleeding into the airways, or complications of surgery including lung and/or liver transplantation. Despite their many problems, people with cystic fibrosis may lead productive lives and often attend school or work until shortly before death.

More Information

The following English-language resource may be useful. Please note that THE MANUALS is not responsible for the content of this resource.

  • Cystic Fibrosis Foundation: A resource that provides information about available treatment options, drug development, research, and community support services

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