What is a cough?

A cough is the body’s natural way of clearing mucus and irritating substances from the lungs, airways and throat. It is a natural process that prevents substances other than air from entering the lungs, but it can make breathing difficult.

Types of cough

Depending on its cause, a cough can be wet, dry or barking. It can also be acute (lasting less than two weeks) or chronic (lasting more than four weeks).

  • Children with asthma often have a cough that includes wheezing and fast breathing.
  • Children with croup have a cough that sounds like a bark. When they breathe in, it sounds noisy, but breathing may be normal when they are not coughing.
  • Children with pertussis (whooping cough) often have forceful spasms of coughing. These coughs have a “whoop” sound.

If your child has only a mild cough or a cough and a runny nose, they usually get better within one or two weeks.

Causes of coughs


The most common cause of a cough is an upper respiratory infection caused by a virus.

A respiratory infection, such as the common cold, can cause mucus to build up in the nose. If this mucus drips from the nose into the throat, the body will cough so that the mucus will not enter the lungs.

This automatic coughing is due to a “cough reflex”, a signal that travels between the brain and nerves in the airways. These nerves can become very sensitive during a viral respiratory infection. If they remain sensitive after the infection clears, or if an infection lingers, a child can develop a prolonged or chronic cough.

A bacterial infection of the upper respiratory tract or of the lower respiratory tract (lungs) can also cause a cough. Bacterial infections of the lungs can be more serious and require antibiotic treatment.

Exposure to irritating substances

Substances that irritate the airway, such as second-hand smoke, can also cause a cough in children. Chronic coughs can result from exposure to an irritant over a long period.

Foreign objects in the airway

Young children who have swallowed a small object or choked on a small piece of food may have a sudden onset of severe coughing or difficulty breathing. This is a medical emergency.

Sometimes foreign objects can cause a persistent cough that can last for weeks or months. Your child’s doctor can identify and treat the problem.

How to care for a cough at home

Help your child get enough sleep

When your child has a cough, they may have difficulty sleeping. Their breathing is slower and shallower and they may need to cough during the night to keep their lungs clear of mucus.

  • If a baby has a cough because of congestion in the nose, consider using a saline nasal wash and an aspirator to suck the mucus out of their nose. These products are available over-the-counter and may help your baby breathe more easily while they sleep.
  • An older child with a cough may be more comfortable sleeping with their head raised on a pillow.

If your child cannot sleep well at night, let them rest more during the day.

Offer small glasses of fluid often

Encourage your child to drink fluids to help them feel better. If your child is vomiting (throwing up) after coughing, encourage them to drink small amounts of fluids more often.

Use humidity to loosen any mucus

Dry air tends to make coughs worse. A barky cough may get better after your child is exposed to humidified air, such as the steam from a shower. In the same way, a cool mist vaporizer or humidifier in your child’s bedroom may offer relief. If using a vaporizer, change the water and clean any filters at least once a day.

Do not change your child’s diet

You can and should continue breastfeeding a baby if they have a cough. Feeding your baby smaller amounts more often may help.

Older children can continue to eat any type of solids or liquids. You do not need to remove milk from your child’s diet, as it does not create or increase mucus.

Offer honey

Children over 12 months old can take 1 to 2 teaspoons (5 to 10 mL) of pasteurized honey as needed to ease a cough. Do not give honey to babies under 12 months because of the risk of botulism (a disease that results from a toxin produced by bacteria in the honey).

Other home remedies for cough are not recommended.

Avoid cough medicine

Cough and cold medicines are not recommended for children under age six years of age. Never give them to a child under age two. Cough syrups have side effects and can be dangerous or even lethal in young children because of certain ingredients.

Children over the age of six may take a cough and cold medicine, but they have not been proven to reduce the length of a cough.

Avoid smoky places

Keep your child away from smoky places and other environmental irritants. Exposure to cigarette smoke can make coughs worse, especially if your child has reactive airways or asthma.

When to see a doctor

If your child has a cough, see your child’s doctor if they:

  • have difficulty breathing
  • have a fever​
  • have a blocked nose
  • have the cough for over two weeks.

Tell your child’s doctor if your child has been exposed to possible infections or irritating substances.

Go to your nearest emergency department or call 911 if your child:

  • is unable to feed due to a cough
  • is vomiting often because of a cough
  • is choking on food or some other object
  • has a barking cough and noisy breathing
  • has breathing difficulties that do not settle after spending time in humid air
  • has trouble catching their breath
  • has blue lips or skin
  • has a persistent cough.

Key points

  • Most coughs are due to common viruses and do not require treatment.
  • To ease a cough, offer honey to children aged 12 months and older, expose your child to humid air and let your child get plenty of rest in a comfortable position.
  • You do not need to change your child’s diet. Over-the-counter cough and cold medicines are not recommended for children under age six.
  • See your child’s doctor if your child has a fever or breathing difficulties. Call 911 or go the nearest emergency department if your child is vomiting often, unable to feed or has noisy breathing because of a cough.

Janine A. Flanagan, HBArtsSc, MD, FRCPC