The most common cause is severe or repeated respiratory infections, often in people who have an underlying problem with their lungs or immune system.
Most people develop a chronic cough that often results in mucus production, and some also cough up blood and have chest pain and recurrent episodes of pneumonia.
Chest x-rays, computed tomography, and breathing tests are usually done to determine the extent and severity of the disorder.
People often are given inhaled medications, antibiotics, and other measures to suppress and clear the buildup of mucus.
Bronchiectasis can result when conditions
Directly injure the bronchial wall
Indirectly lead to injury by interfering with normal airway defenses
Airway defenses include the mucus layer and tiny projections (cilia) on the cells that line the airways. These cilia beat back and forth, moving the thin liquid layer of mucus that normally coats the airways. Harmful particles and bacteria trapped in this mucus layer are moved up to the throat and coughed out or swallowed.

Whether airway injury is direct or indirect, areas of the bronchial wall are damaged and become chronically inflamed. The inflamed bronchial wall becomes less elastic, resulting in the affected airways becoming widened (dilated) and developing small outpouchings, or sacs, that resemble tiny balloons. Inflammation also increases secretions (mucus). Because cells with cilia are damaged or destroyed, these secretions accumulate in the widened airways and serve as a breeding ground for bacteria. The bacteria further damage the bronchial wall, leading to a vicious cycle of infection and airway damage.
Understanding Bronchiectasis
In bronchiectasis, mucus production increases, the cilia are destroyed or damaged, and areas of the bronchial wall become chronically inflamed and are destroyed. ![]() |
Bronchiectasis may affect many areas of the lung (diffuse bronchiectasis), or it may appear in only one or two areas (focal bronchiectasis). Typically, bronchiectasis causes widening of medium-sized airways, but often smaller airways become scarred and destroyed.
Complications
The inflammation and infection can extend to the small air sacs of the lungs (alveoli) and cause pneumonia Overview of Pneumonia Pneumonia is an infection of the small air sacs of the lungs (alveoli) and the tissues around them. Pneumonia is one of the most common causes of death worldwide. Often, pneumonia is the final... read more , scarring, and a loss of functioning lung tissue (see also Overview of the Respiratory System Overview of the Respiratory System To sustain life, the body must produce sufficient energy. Energy is produced by burning molecules in food, which is done by the process of oxidation (whereby food molecules are combined with... read more ). Severe scarring and loss of lung tissue can ultimately strain the right side of the heart as it tries to pump blood through the altered lung tissue. The right-sided heart strain can lead to a form of heart failure called cor pulmonale Cor Pulmonale Cor pulmonale is enlargement and thickening of the ventricle on the right side of the heart resulting from an underlying lung disorder that causes pulmonary hypertension (high pressures in the... read more .
Very severe (advanced) cases of bronchiectasis occur more commonly in people who have advanced cystic fibrosis and, in areas where people live in crowded conditions and/or lack access to medical care, those with tuberculosis. Very severe bronchiectasis may impair breathing enough to cause abnormally low levels of oxygen and/or high levels of carbon dioxide in the blood, a condition called chronic respiratory failure.
Causes of Bronchiectasis
The most common cause of bronchiectasis is severe or repeated respiratory infections, which are particularly likely to occur in people who have one or more of the following:
Other hereditary disorders, such as primary ciliary dyskinesia, in which the ability to clear the airways is impaired
Certain autoimmune disorders Autoimmune Disorders An autoimmune disorder is a malfunction of the body's immune system that causes the body to attack its own tissues. What triggers an autoimmune disorder is not known. Symptoms vary depending... read more , such as rheumatoid arthritis Rheumatoid Arthritis (RA) Rheumatoid arthritis is an inflammatory arthritis in which joints, usually including those of the hands and feet, are inflamed, resulting in swelling, pain, and often destruction of joints.... read more
, ulcerative colitis Ulcerative Colitis Ulcerative colitis is a chronic inflammatory bowel disease in which the large intestine (colon) becomes inflamed and ulcerated (pitted or eroded), leading to flare-ups (bouts or attacks) of... read more , or Sjögren syndrome Sjögren Syndrome Sjögren syndrome is a common autoimmune connective tissue disorder and is characterized by excessive dryness of the eyes, mouth, and other mucous membranes. White blood cells can infiltrate... read more
Mechanical factors, such as airway blockage caused by an inhaled object, chronically enlarged lymph nodes, changes after lung surgery, or a lung tumor
Inhaling toxic substances that injure the airways, such as noxious fumes, gases, smoke (including tobacco smoke), and injurious dust (for example, silica and coal dust)
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 , which affects the larger airways, can cause mucus plugs that block the airways and lead to bronchiectasis. It is an allergic reaction to the fungus Aspergillus and occurs most commonly in people with asthma Asthma Asthma is a condition in which the airways narrow—usually reversibly—in response to certain stimuli. Coughing, wheezing, and shortness of breath that occur in response to specific triggers are... read more or cystic fibrosis.
In places where tuberculosis Tuberculosis (TB) Tuberculosis is a chronic contagious infection caused by the airborne bacteria Mycobacterium tuberculosis. It usually affects the lungs, but almost any organ can be involved. Tuberculosis... read more is common, tuberculosis is often the cause of severe or repeated infections that cause bronchiectasis. Poor nutrition and unavailability of vaccines to prevent various respiratory infections can also contribute.
In many people with bronchiectasis, a cause cannot be determined despite a thorough evaluation.
Symptoms of Bronchiectasis
Bronchiectasis can develop at any age. In most people, symptoms begin gradually, usually after a respiratory infection, and tend to worsen over the years. Most people develop a chronic cough that produces thick sputum. The amount and type of sputum depend on the extent of the disease and whether there is a complicating infection (often called a disease flare or exacerbation). Often, people have coughing spells only early in the morning and late in the day.
Coughing up of blood Coughing Up Blood Coughing up blood from the respiratory tract is called hemoptysis. The amount of blood produced can vary from a few streaks of blood mixed with normal sputum to large amounts of pure blood.... read more (hemoptysis) is common because the damaged airway walls are fragile and have increased numbers of blood vessels. Hemoptysis may be the first or only symptom.
Recurrent fever or chest pain, with or without frequent bouts of pneumonia Overview of Pneumonia Pneumonia is an infection of the small air sacs of the lungs (alveoli) and the tissues around them. Pneumonia is one of the most common causes of death worldwide. Often, pneumonia is the final... read more , may also occur. People with widespread bronchiectasis may develop wheezing or shortness of breath. People whose bronchiectasis progresses to cor pulmonale or chronic 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 also have fatigue, lethargy, and worsening shortness of breath, particularly during exertion. If bronchiectasis is severe and chronic, people commonly lose weight.
People may have flares (exacerbations) of disease, sometimes with pneumonia. Exacerbations may result from a new or worsening infection. When an exacerbation occurs, people may have more severe cough, increased sputum production, or worsening of breathing difficulties.
Diagnosis of Bronchiectasis
Chest x-ray
Computed tomography
Pulmonary function tests
Specific tests for suspected causes
Doctors may suspect bronchiectasis because of a person’s symptoms or the presence (currently or in the past) of a condition thought to cause bronchiectasis.
Tests are done to
Confirm the diagnosis
Assess the extent of the disease
Identify the cause of the disease
Chest x-rays Chest Imaging Chest imaging studies include X-rays Computed tomography (CT) CT angiography Magnetic resonance imaging (MRI) read more can often detect the lung changes caused by bronchiectasis. However, occasionally, x-ray results are normal. Computed tomography (CT) is the most accurate test to identify and confirm the diagnosis and to determine the extent and severity of the disease.
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 are done to assess how well the lungs are working. These tests measure how well the lungs are able to hold air, to move air in and out, and to exchange oxygen and carbon dioxide. Pulmonary function tests do not diagnose bronchiectasis but do help doctors determine how severe the lung disorder is and are useful for monitoring its progression over time.
After bronchiectasis is diagnosed, tests are often done to check for disorders that may be causing or contributing to it. Such tests may include the following:
Testing for human immunodeficiency virus (HIV) infection Human Immunodeficiency Virus (HIV) Infection Human immunodeficiency virus (HIV) infection is a viral infection that progressively destroys certain white blood cells and is treated with antiretroviral medications. If untreated, it can cause... read more
and other immune system and autoimmune disorders
Measuring the salt level in sweat (which is abnormal in people with cystic fibrosis Cystic Fibrosis )
Testing nasal, bronchial, or sputum specimens for evidence of infectious organisms
Doing other tests to determine if the cilia are structurally or functionally defective
Testing for 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 , tuberculosis Tuberculosis (TB) Tuberculosis is a chronic contagious infection caused by the airborne bacteria Mycobacterium tuberculosis. It usually affects the lungs, but almost any organ can be involved. Tuberculosis... read more
, and alpha-1 antitrypsin deficiency Alpha-1 Antitrypsin Deficiency Alpha-1 antitrypsin deficiency is a hereditary disorder in which a lack or low level of the enzyme alpha-1 antitrypsin damages the lungs and liver. Alpha-1 antitrypsin deficiency is caused by... read more
When bronchiectasis is limited to one area—for example, a lung lobe or segment—doctors may do a bronchoscopy Bronchoscopy Bronchoscopy is a direct visual examination of the voice box (larynx) and airways through a viewing tube (a bronchoscope). A bronchoscope has a camera at the end that allows a doctor to look... read more to determine whether an inhaled foreign object or lung tumor is the cause.
Sweat chloride tests and genetic testing for cystic fibrosis Cystic Fibrosis may be needed when there is a family history, repeated respiratory infections, or other unusual findings in a child or adult, even when other typical features of cystic fibrosis are absent.
Doctors may take a sputum sample and send it to a laboratory to grow (culture) the bacteria to determine which bacteria are present and what antibiotics are most effective against these bacteria. This testing can help determine the best antibiotics to use during flares.

Treatment of Bronchiectasis
Vaccination to prevent infections that cause or worsen bronchiectasis
Antibiotics to treat infections that cause or worsen bronchiectasis
Drainage of airway secretions with therapies that promote cough (such as, chest physical therapy, regular exercise, other techniques
Inhaled medications that help thin or loosen thick mucus so it can be more easily coughed out
Inhaled bronchodilators and sometimes inhaled corticosteroids
Sometimes, oral or inhaled antibiotics to suppress certain bacteria and prevent recurring infections
Rarely, surgical removal of part of lung
Oxygen therapy, if needed
Treatment of bronchiectasis is directed toward reducing the frequency of infections when possible, preventing certain infections with vaccines and sometimes antibiotics, decreasing the buildup of mucus, decreasing inflammation, and relieving airway blockage. Early, effective treatment can reduce complications such as hemoptysis, low oxygen levels in the blood, respiratory failure, and cor pulmonale Cor Pulmonale Cor pulmonale is enlargement and thickening of the ventricle on the right side of the heart resulting from an underlying lung disorder that causes pulmonary hypertension (high pressures in the... read more . Treatment of underlying conditions that cause or contribute to flares is also needed.
Flares (exacerbations) are treated with antibiotics, bronchodilators, and chest physiotherapy 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 to promote drainage of secretions and mucus. Chest physiotherapy includes such techniques as postural drainage Postural drainage 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
and chest percussion. Sometimes antibiotics are given for a long period to prevent recurring infections, especially in people who have frequent flares or cystic fibrosis. Most people with cystic fibrosis benefit from treatment with a cystic fibrosis transmembrane regulator (CFTR) modulator, which can decrease exacerbations.
Inflammation and the buildup of mucus may be helped by humidification of the air and inhaling an aerosolized salt water solution. Medications that thin the thick sputum (mucolytics) may also be given to people who have cystic fibrosis Cystic Fibrosis . In other people, the effectiveness of mucolytics is uncertain.
Bronchial blockage can be detected and treated by bronchoscopy Bronchoscopy Bronchoscopy is a direct visual examination of the voice box (larynx) and airways through a viewing tube (a bronchoscope). A bronchoscope has a camera at the end that allows a doctor to look... read more before severe damage occurs.
Significant bleeding with cough is sometimes treated with a technique called embolization instead of surgery. In embolization, doctors use a catheter to inject a substance that blocks the vessel that is bleeding.
Low blood oxygen levels are treated with oxygen therapy Oxygen Therapy Oxygen therapy is a treatment that delivers extra oxygen to the lungs when the level of oxygen in the blood is too low. Oxygen is a gas that makes up about 21% of the air we breathe. The lungs... read more . Appropriate use of oxygen may help prevent complications such as cor pulmonale Cor Pulmonale Cor pulmonale is enlargement and thickening of the ventricle on the right side of the heart resulting from an underlying lung disorder that causes pulmonary hypertension (high pressures in the... read more . If people have wheezing or shortness of breath, bronchodilators and sometimes inhaled corticosteroids often help. If a person has a flare, usually these medications and an antibiotic are given, and oral corticosteroids are added in some cases. 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 , if present, should be treated.
Rarely, part of a lung needs to be surgically removed. Such surgery usually is an option only if the disease is confined to one lung or, preferably, to one lung lobe or segment. Surgery may be considered for people who have recurrent infections despite treatment or who cough up large amounts of blood.
Advanced bronchiectasis in some people—mostly those who also have advanced cystic fibrosis—can be treated with 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 . Pulmonary function (as measured by the amount of air in the lungs and the rate and amount of air moving in and out of the lungs with each breath) usually improves within 6 months, and the improvement may be sustained for at least 5 years.
Prognosis for people with bronchiectasis depends on its cause and on how well infections and other complications are prevented or controlled. People with coexisting conditions, such as chronic bronchitis Chronic Obstructive Pulmonary Disease (COPD) Chronic obstructive pulmonary disease is persistent narrowing (blocking, or obstruction) of the airways occurring with emphysema, chronic obstructive bronchitis, or both disorders. Cigarette... read more or emphysema Chronic Obstructive Pulmonary Disease (COPD) Chronic obstructive pulmonary disease is persistent narrowing (blocking, or obstruction) of the airways occurring with emphysema, chronic obstructive bronchitis, or both disorders. Cigarette... read more
, and people who have complications, such as pulmonary hypertension Pulmonary Hypertension Pulmonary hypertension is a condition in which blood pressure in the arteries of the lungs (the pulmonary arteries) is abnormally high. Many disorders can cause pulmonary hypertension. People... read more or cor pulmonale, tend to have a worse prognosis.
Prevention of Bronchiectasis
Early identification and treatment of conditions that tend to cause bronchiectasis may prevent its development or reduce its severity. More than half the cases of bronchiectasis in children can be accurately diagnosed and promptly treated.
Childhood immunizations Overview of Immunization Immunization (vaccination) helps the body defend itself against diseases caused by certain bacteria or viruses. Immunity (the ability of the body to defend itself against diseases caused by... read more against measles and pertussis (whooping cough), improved living conditions, and better nutrition have markedly reduced the number of people who develop bronchiectasis. Pneumococcal vaccination Pneumococcal Vaccine Pneumococcal vaccines help protect against bacterial infections caused by Streptococcus pneumoniae (pneumococci). Pneumococcal infections include ear infections, sinusitis, pneumonia... read more , COVID-19 vaccination 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 , annual influenza vaccination 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 , and use of appropriate antibiotics early in the course of lung infections help to prevent bronchiectasis or reduce its severity.
Other specific steps that can be taken include the following:
Receiving immunoglobulin for an immunoglobulin deficiency syndrome may prevent recurring infections.
In people who have allergic bronchopulmonary aspergillosis, using corticosteroids appropriately—and sometimes an antifungal medication (such as itraconazole)—may reduce the bronchial damage that results in bronchiectasis.
Giving the enzyme alpha-1 antitrypsin to people with alpha-1 antitrypsin deficiency may help prevent the disorder from becoming more severe.
Avoiding toxic fumes, gases, smoke, and injurious dusts also helps prevent bronchiectasis or reduce its severity.
Watching what children put in their mouth can help prevent them from inhaling foreign objects into the airways.
Avoiding oversedation due to medication, illicit drugs, or alcohol and seeking medical care for neurologic symptoms (such as impaired consciousness) or gastrointestinal symptoms (such as difficulty in swallowing and regurgitation or coughing after eating) may help to prevent aspiration.
Avoiding use of mineral oil or petroleum jelly in the nose may prevent accidental inhalation of these substances into the lungs.
More Information
The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.
American Lung Association: Bronchiectasis: Complete discussion of symptoms, diagnosis, and treatment, and tips on questions to discuss with the doctor
National Heart. Lung, and Blood Institute: Bronchiectasis: Complete discussion of symptoms, diagnosis, and treatment, and tips on questions to discuss with the doctor