Cough

A cough is a reflex action to clear your airways of mucus and irritants such as dust or smoke.

Coughs may be 'dry or 'chesty'. They are also classified according to how long they last:

• acute cough lasts for less than three weeks,
• subacute cough gets better over a three-to-eight-week period, and
• chronic (persistent) cough lasts for longer than eight weeks.

Coughs caused by the common cold or by flu usually clear up after a few days. Most coughs clear up within two weeks. 

What are the causes?

Most people with a cough have a respiratory tract infection caused by a virus, such as the common cold, flu or bronchitis.

A persistent cough in adults may be caused by smoking, a condition such as rhinitis or asthma, or a prescribed medicine such as an ACE-inhibitor (to treat heart disease).

In children, a persistent cough may indicate a more serious respiratory tract infection such as whooping cough.

For more information on conditions causing cough, go to Causes.

When to see your doctor

If you have had a cough for more than two weeks following a viral infection, or if your cough is progressively getting worse, see your GP.

Glossary

Inflammation

Inflammation is the body's response to infection, irritation or injury, which causes redness, swelling, pain and sometimes a feeling of heat in the affected area.

Embolism

An embolism is the sudden blockage of a blood vessel, usually by a blood clot or air bubble.