A cough is not usually serious and most often will go away within 2 to 4 weeks. There are things you can do to make life easier while you’ve got a cough. It’s also good to know when you should see your doctor.
This page is about cough in adults. Find out about cough in children.
- A cough is an automatic reaction to clear your airways if they are blocked by something, such as phlegm (mucus), smoke, dust or a piece of food.
- Most coughs clear up on their own and you can take care of yourself without visiting your doctor. However, if your cough lasts for more than three weeks, then see your doctor.
- A cough is often the main symptom of a viral infection in your throat, main airway or the airways going into your lungs.
- A cough may be productive or unproductive. A productive cough produces phlegm (mucus from the back of your throat, nose or sinuses or up from your lungs). An unproductive cough is a dry, often hacking cough.
|If you have a cough and you’re short of breath, cough up blood or have unexplained problems like weight loss or a high temperature (fever), you should see your GP urgently.|
What causes a cough?
The most common cause of a cough is a viral infection such as a cold or the flu.
Other common causes include:
- allergies, such as hayfever
- whooping cough
- gastro-oesophageal reflux disease (GORD)
- chronic obstructive pulmonary disease (COPD)
- side effects of some medicine, such as angiotensin-converting enzyme inhibitor (also called ACE inhibitors, for example, cilazapril, enalapril, lisinopril).
Rare causes include:
How is the cause of a cough diagnosed?
Your doctor will ask some questions about your cough, such as:
- did it start suddenly or develop over time? Did anything trigger it? How long has it lasted?
- when do you cough? Is it worse when you exercise?
- are you breathless even when you're not coughing? Have you got any pain in your chest?
- are you coughing up phlegm (mucus)? What colour is it? Is there any blood?
- do you feel ill? Do you have a high temperature (fever), weight loss or sweats?
- have you lost weight?
- have you been in contact with anyone with TB or travelled overseas recently?
- do you smoke?
- what is your job?
- have you started any new medicine recently?
They may also listen to your chest, and take a sample of any mucus you might be coughing up, order an X-ray, allergy test or test to see how well your lungs work.
What is the treatment for a cough?
In most cases, treatment for cough is not necessary, especially for mild, short-term coughs because it's likely to be a viral infection that will get better on its own within a few weeks. You can care for yourself by:
- drinking plenty of fluids, including lemon and honey drinks
- sleeping with your head propped up on pillows
- avoiding smoke, and if you smoke, quit smoking
- using your inhaler if you have asthma.
Medicines used to treat cough are aimed at treating the specific cause.
- If your cough is due to allergies, you may be prescribed antihistamines to prevent your allergies, such as loratadine or cetrizine. Read more about antihistamines.
- Decongestants may be helpful if your cough is caused by a post-nasal drip or a congested nose. These help to relieve stuffiness or congestion of the nostrils. Read more about nasal decongestants.
- If your cough is due to asthma or COPD, your doctor may prescribe medication called bronchodilators which open the airways and help make it easier to breathe. In severe cases, you may be prescribed corticosteroids such as prednisone.
- Antibiotics are only prescribed if the cough is caused by a bacterial infection.
There are a number of cough medicines available on the market. They may be sold in combination with other medicines in cold and cough products, or as cough mixtures or cough lozenges.
Cough medicine doesn’t cure a cough but may give you some relief from it. There is little evidence to suggest that cough medicine is any more effective than simple home remedies, and they're not suitable for everyone. Examples of cough medicines include:
- cough suppressants, which are used for dry coughs and may control the urge to cough such as dextromethorphan, pholcodine and codeine.
- expectorants, which are used for productive coughs. They loosen mucus making it easier to cough up. It is unclear whether expectorants actually work. Examples of an expectorant found in cold and cough medicines is guaifenesin.
How can I prevent getting a cough?
Cough Ministry of Health, New Zealand
Cough, colds and sore throats – manage symptoms without antibiotics Choosing Wisely, NZ
Cough Health Direct, Australia
Cough NHS Choices, UK