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 (see below) and most coughs clear up within three weeks.

Treatment isn't usually necessary, but a home remedy containing honey and lemon may help ease a short-term cough.

There's little evidence to suggest that cough medicines will be any more effective.

Read more about cough treatments.

Dry or chesty cough?

Dry coughs are usually felt in the throat as a tickle that sets off the coughing.

It happens when the throat and upper airways become inflamed (swollen). No phlegm (thick mucus) is produced.

The common cold or flu causes a dry cough because your brain thinks the inflammation in your throat and upper airways is a foreign object and tries to remove it by coughing.

A chesty cough usually produces phlegm. The cough is helpful, because it clears the phlegm from your lung passages.

When to see your GP

See your GP if you've had a cough for more than three weeks after a viral infection, or if your cough is progressively getting worse.

If you experience breathing difficulties, chest pain or you cough up blood, speak to your GP immediately.

If your GP is unsure what's causing your cough they may refer you to a respiratory specialist. They may also request some tests, including:

• a chest X-ray - to see if you have a chest infection
• taking a sample of your phlegm for analysis - to help decide if antibiotics should be prescribed
• spirometry (breathing in and out of a tube connected to a machine) - to see if you have an underlying respiratory condition
• allergy testing - to see whether your cough is caused by something you're allergic to, such as house dust mites

What causes a cough?

Most people with a cough have a respiratory tract infection caused by a virus. Possible non-infectious causes include:

• allergic rhinitis, such as hay fever
• a flare-up of a long-term condition such as asthma, chronic obstructive pulmonary disease (COPD) or chronic bronchitis
• gastro-oesophageal reflux disease - due to irritation and damage caused by stomach acid 
• smoking

In rare cases it may be the first sign of a condition causing a long-term cough.

Read more about the causes of a cough.