Chest
Cough
A reflex to clear the airways that is usually caused by a viral infection and settles within a few weeks, but which when persistent, productive or accompanied by breathlessness or blood can point to a chest condition needing assessment.
Education and reference only. This explains the common causes of cough and the warning signs that need urgent help, in plain language — it is not a diagnosis or a substitute for advice from a clinician. If you feel very unwell or are worried, seek medical help.
Quick answer
What is cough?
Coughing is a protective reflex that clears irritants, mucus and infection from the airways, so most coughs are a normal and useful response to a common cold or other viral infection and clear up within two to three weeks. Coughs are loosely grouped by how long they last: acute coughs lasting under three weeks are usually viral, while a cough persisting beyond about eight weeks is called chronic and is more likely to have an identifiable cause such as asthma, acid reflux, smoking-related lung disease or post-infectious airway sensitivity.
- Get urgent help: Call 999 if you are coughing and cannot breathe properly, or are gasping and unable to speak in full sentences. Seek urgent help if you cough up blood, or phlegm that is rusty or blood-streaked.
- Self-care: Most coughs from colds and viruses need only time and comfort measures.
About cough
Coughing is a protective reflex that clears irritants, mucus and infection from the airways, so most coughs are a normal and useful response to a common cold or other viral infection and clear up within two to three weeks. Coughs are loosely grouped by how long they last: acute coughs lasting under three weeks are usually viral, while a cough persisting beyond about eight weeks is called chronic and is more likely to have an identifiable cause such as asthma, acid reflux, smoking-related lung disease or post-infectious airway sensitivity. The nature of the cough offers clues — a dry, tickly cough differs from a wet, productive one that brings up phlegm. Most coughs need only patience and simple self-care, but a cough that brings up blood, that comes with significant breathlessness, fever or weight loss, or that persists for many weeks should be investigated.
When to get help
Call 999 or go to A&E if cough comes with any of these warning signs:
- Call 999 if you are coughing and cannot breathe properly, or are gasping and unable to speak in full sentences.
- Seek urgent help if you cough up blood, or phlegm that is rusty or blood-streaked.
- Seek urgent help for a cough with severe breathlessness, chest pain, or blue lips.
- See a doctor promptly for a cough lasting more than three weeks, or any cough with unexplained weight loss or night sweats.
- Seek prompt help for a cough with high fever and feeling very unwell, especially with a fast breathing rate.
When to see a doctor
A cough that comes with severe breathlessness, blood, chest pain or blue lips needs urgent help. See a doctor promptly for any cough that lasts more than three weeks, that keeps coming back, or that is accompanied by unexplained weight loss, drenching night sweats, fevers or a marked change in a long-standing smoker's cough. People with known lung conditions should seek help if their cough or phlegm changes character or fails to settle as usual. A cough in a baby or young child that causes breathing difficulty always warrants prompt assessment.
Not sure how urgent it is? It is always OK to call NHS 111 for advice, day or night.
What can cause it
Common causes of cough
Cough has many possible causes. Each links to a full, plain-language guide to that condition — what it is, how it's treated and when to seek help.
What helps
Self-care and what you can do
Most coughs from colds and viruses need only time and comfort measures. Rest, drink plenty of fluids to stay hydrated and to loosen mucus, and try warm drinks; a spoon of honey in warm water can soothe a tickly throat in adults and children over one year. Keep the air from getting too dry, avoid smoke and other irritants, and stop smoking if you can, as it both causes and worsens coughs. Sleeping slightly propped up can ease a cough that is worse at night, and if reflux seems to be the trigger, eating earlier and smaller meals may help. If you have asthma or another lung condition, follow your usual plan and treatments during a cough.
Answers
Cough: frequently asked questions
How long should a cough last before I worry?
Most coughs from colds clear within two to three weeks. A cough lasting more than three weeks, or one with breathlessness, blood, weight loss or night sweats, should be assessed by a doctor.
Should I be worried about coughing up blood?
Coughing up blood, or blood-streaked or rusty phlegm, should always be checked urgently. While the cause is often minor, it can occasionally signal a serious chest problem that needs investigation.
Why is my cough worse at night?
A cough that worsens lying down can be due to mucus dripping down the throat, acid reflux irritating the airways, or asthma, which often flares overnight. Propping yourself up can help, and a persistent night cough is worth assessing.
Do I need antibiotics for a cough?
Most coughs are viral and do not improve with antibiotics. They are only helpful when a bacterial chest infection is suspected. A clinician will decide based on your symptoms and examination rather than the cough alone.
Sources
Where this is drawn from
- NICE CKS: Cough.
- Asthma + Lung UK: living with a cough.
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