Cough helps clear materials from the airways and prevent them from going to the lungs. The materials may be particles that have been inhaled or substances from the lungs and/or airways. Most commonly, material coughed up from the lungs and airways is sputum (also called phlegm—a mixture of mucus, debris, and cells ejected from the lungs). But sometimes a cough brings up blood. A cough that brings up either is considered productive. Older children (and adults) typically cough material out, but younger children usually swallow it. Some coughs do not bring anything up. They are considered dry or nonproductive.
Cough is one of the most common reasons parents bring their children to a health care practitioner.
(See also Cough in Adults.)
Causes
Likely causes of cough depend on whether the cough has lasted less than 4 weeks (acute) or 4 weeks or more (chronic).
Common causes
For acute cough, the most common cause is
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An upper respiratory infection due to a virus
For chronic cough, the most common causes are
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Asthma (the most common)
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Postnasal drip (drainage of fluid from the nose down the throat)
Less common causes
Acute cough may also result from a foreign body (such as a piece of food or a piece of a toy) inhaled into the lungs (aspiration) or less common respiratory infections such as pneumonia, pertussis (whooping cough), or tuberculosis.
Chronic cough may also result from aspiration of a foreign body, hereditary disorders such as cystic fibrosis or primary ciliary dyskinesia, a birth defect of the airways or lungs, inflammatory disorders involving the airways or lungs, or may be stress-related (also known as a habit or psychogenic cough).
Evaluation
Not every cough requires immediate evaluation by a doctor. Knowing which symptoms may indicate a serious cause can help parents decide whether contacting a doctor is needed.
Warning signs
When to see a doctor
Children who have warning signs should be taken to a doctor right away, as should those whose parents think they may have inhaled a foreign body. If children have no warning signs but have a frequent harsh or barking cough, parents should call the doctor. Doctors typically want to see such children within a day or so, depending on their age, other symptoms (such as fever), and medical history (particularly a history of lung disorders, such as asthma or cystic fibrosis). Otherwise healthy children who have a cough occasionally and have typical cold symptoms (such as a runny nose) may not need to be seen by a doctor.
Children with a chronic cough and no warning signs should be seen by a doctor, but a delay of a few days to a week is generally not harmful.
What the doctor does
Doctors first ask questions about the child's symptoms and medical history. Doctors then do a physical examination. What they find during the history and physical examination often suggests a cause of the cough and the tests that may need to be done (see Table: Some Causes and Features of Cough in Children).
Information about the cough helps a doctor determine its cause. Therefore, a doctor may ask
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What time of day does the cough occur?
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What factors—such as cold air, body position, talking, eating, drinking, or exercise—trigger or relieve the cough?
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What does the cough sound like?
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Did symptoms begin suddenly or gradually?
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What are the child’s other symptoms?
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Does the cough bring up sputum or blood?
A nighttime cough can be caused by asthma or postnasal drip. Coughing at the beginning of sleep and in the morning when waking usually is caused by inflammation of the sinuses (sinusitis). Coughing in the middle of the night is more consistent with asthma. A barky cough suggests croup or sometimes a cough that is left over from a viral upper respiratory infection. A cough that started suddenly in a child with no other symptoms suggests possible inhalation of a foreign body. Contrary to what many people think, whether sputum is yellow or green or thick or thin does not help distinguish bacterial infection from other causes.
When children are 6 months to 4 years old, parents are asked about the possibility of swallowing a foreign body (such as a small toy) or small, smooth, firm foods (such as peanuts or grapes). Doctors also ask whether the child has had any recent respiratory infections, frequent bouts of pneumonia, allergies, or asthma or has been exposed to tuberculosis or other infections, as may occur during travel to certain countries.
A physical examination is done. To check for breathing problems, doctors observe the child's chest, listen to it with a stethoscope, and tap (percuss) it. Doctors also check for cold symptoms, swollen lymph nodes, and abdominal pain.
Some Causes and Features of Cough in Children
Cause |
Common Features* |
Tests |
Acute cough (lasting less than 4 weeks) |
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At first, symptoms of a cold Wheezing and, if bronchiolitis is severe, rapid breathing, with flared nostrils, and difficulty breathing Possibly vomiting after coughing Typically in infants up to 24 months old, most often in those 3–6 months old |
A doctor’s examination Sometimes a chest x-ray and culture of mucus from the nose (taken with a swab) to identify the virus |
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COVID-19 |
Fever, cough, runny nose, rapid breathing, sore throat, shaking chills, headache, loss of taste or smell, vomiting, diarrhea, belly pain, rash, red eyes Particularly when there are known cases in the community |
Sometimes testing with a nasal swab |
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At first, symptoms of a cold Then a frequent, barky cough (worse at night) and, when croup is severe, a loud squeaking noise when the child breathes in (stridor) and rapid breathing, with flared nostrils Typically in children 6 months to 3 years old |
A doctor’s examination Sometimes a neck and chest x-ray |
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A foreign object in the windpipe (trachea) or larger airways of the lungs (bronchi) |
Cough and choking that begin suddenly No fever initially No symptoms of a cold Typically in children 6 months to 4 years old |
A chest x-ray Sometimes bronchoscopy |
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Pertussis (whooping cough) |
Mild coldlike symptoms for 1–2 weeks, followed by coughing fits Infants: Coughing fits that may be associated with a blue tint to the lips or skin (cyanosis), vomiting after coughing, or pauses in breathing (apnea) Older children: Coughing fits that may be followed by a prolonged, high-pitched sound (called the whoop) Cough that may persist for several weeks |
Culture of a sample of mucus taken from the nose |
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Typically fever Sometimes wheezing, shortness of breath, and chest pain Cough that is sometimes productive |
A doctor's examination Often a chest x-ray |
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Coughing at the beginning of sleep or in the morning with waking Sometimes chronic discharge from the nose |
A doctor's examination Sometimes CT of the sinuses |
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Upper respiratory infections (most common) |
A runny nose and nasal congestion Possibly fever and sore throat Possibly small, nontender, swollen lymph nodes in the neck |
A doctor’s examination |
Chronic cough† (lasting 4 weeks or more) |
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Periodic attacks of coughing in response to a trigger (such as pollen or other allergens), exposure to cold air, or exercise Coughing during the night Sometimes family members who have asthma |
A doctor’s examination Treatment with asthma drugs to see whether symptoms are relieved Breathing tests to evaluate lung function (pulmonary function tests) |
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Birth defects affecting the lungs |
Several episodes of pneumonia in the same part of the lungs |
Chest x-ray Sometimes CT or MRI |
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Birth defects affecting the windpipe (trachea), esophagus, or both |
Vary by defect Typically in newborns or infants If the trachea has not developed normally, possibly a loud squeaking noise when the child breathes in (stridor) or a barky cough and difficulty breathing If there is an abnormal connection between the trachea and esophagus (tracheoesophageal fistula), a cough or difficulty breathing when the child is fed and frequent bouts of pneumonia |
Chest x-ray Sometimes bronchoscopy and endoscopy If an abnormal trachea is suspected, also CT or MRI |
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A blockage in the intestine by thick secretions (meconium ileus) detected shortly after birth Frequent bouts of pneumonia, sinusitis, or both Not growing as expected (failure to thrive) Enlargement of the fingertips or a change in the angle of the nail bed (clubbing) and nail beds that are tinted blue |
A sweat test Possibly genetic testing to confirm the diagnosis |
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A foreign object in the lung or airways |
Cough and choking that began suddenly Resolution of choking but cough that persists or progressively worsens over several weeks Possibly a fever No symptoms of a cold Typically in children 6 months to 4 years old |
Chest x-rays while breathing out and breathing in Bronchoscopy |
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Infants: Fussiness, spitting up after feedings, arching of the back, or crying after feedings and a cough when lying down Poor weight gain Older children and adolescents: Chest pain or heartburn after meals and when lying down and possibly wheezing, hoarseness, nausea, and regurgitation Cough that is often worse at night |
A doctor's examination Infants: Sometimes an x-ray of the upper digestive tract after barium is given by mouth to determine whether anatomy is normal Treatment with histamine-2 (H2) blockers (if symptoms are relieved, the cause is probably gastroesophageal reflux disease) Sometimes a test to measure acidity or reflux episodes in the esophagus (called a pH probe or an impedance probe) or x-rays taken after formula is given by mouth (gastric emptying scan) to determine the frequency and severity of reflux episodes Older children: Treatment with H2 blockers or proton pump inhibitors to see whether symptoms are relieved Possibly endoscopy |
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Postnasal drip |
Headache, itchy eyes, a mild sore throat particularly in the morning, and coughing at night and when waking up A history of allergies |
Treatment with an antihistamine or a corticosteroid nasal spray (if symptoms are relieved, the cause is an allergy) Possibly x-rays or CT of the sinuses |
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Psychogenic or habit cough |
May develop in children after a cold or other airway irritant Frequent (may be up to every 2–3 seconds), harsh, or honking cough when awake, possibly lasting for weeks to months Cough that stops completely when the child falls asleep Lack of fever or other symptoms |
A doctor's examination Sometimes chest x-rays to look for other causes |
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Recent contact with an infected person Usually a weakened immune system (immunocompromise) Sometimes fever, night sweats, chills, and weight loss |
A chest x-ray A tuberculin skin test |
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* Features include symptoms and the results of the doctor's examination. Features mentioned are typical but not always present. |
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† Children with disorders that cause chronic cough may also be brought to a doctor before 4 weeks. A chest x-ray is always done when children with a chronic cough are first evaluated. |
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CT = computed tomography; MRI = magnetic resonance imaging. |
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Testing
Tests may or may not be needed depending on symptoms and the causes that doctors suspect. For children with warning signs, doctors typically measure the oxygen concentration in blood using a clip-on sensor (pulse oximetry) and take a chest x-ray. These tests are also done if children have a chronic cough or if a cough is worsening. Doctors may also do other tests depending on what they find during the history and physical examination (see Table: Some Causes and Features of Cough in Children).
For children without warning signs, tests are rarely done if the cough has lasted 4 weeks or less and cold symptoms are present. In such cases, the cause is usually a viral infection.
Tests also may not be needed if symptoms strongly suggest a cause. In such cases, doctors may simply start treatment for the presumed cause. However, if symptoms persist despite treatment, tests are often done.
Treatment
Treatment of cough focuses on treating the cause (for example, antibiotics for bacterial pneumonia or antihistamines for allergic postnasal drip).
To relieve cough symptoms, parents have often been advised to use home remedies such as having the child inhale moist air (as from a cool-mist vaporizer or in a hot shower) and drink extra fluids. Although these remedies are harmless, there is little scientific evidence that they make any difference in how children feel.
Cough suppressant drugs (such as dextromethorphan and codeine) are rarely recommended for children. Cough is an important way for the body to clear secretions from the airways. Also, these drugs may have side effects, such as confusion and sedation, and there is very little evidence that they help children feel better or recover more quickly. Expectorants, which are supposed to thin and loosen mucus (making it easier to cough up), are also usually discouraged in children.
Key Points
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Usually, the cause of cough can be identified based on results of the doctor's examination.
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In children aged 6 months to 4 years, a foreign body in the airways must be considered.
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Chest x-rays are taken if children have warning signs or a cough that has lasted more than 4 weeks.
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Usually, cough suppressants and expectorants are not recommended.
