Should I use this page, or skip it?
Use this page if you have a new cough and need how long it should last, whether coloured mucus needs antibiotics, and when to see a GP. Skip it and call 999 for severe breathlessness, chest pain, or blue lips. Use urgent GP or 111 if you cough up blood or feel very unwell.
This page cannot tell you whether you have pneumonia. It is a UK door-chooser for a symptom almost everyone gets. If the main problem is tight, spreading chest pain, stop reading and call 999.
If you already know this is a common cold, you still need the three-week rule and the red flags below. If you live with asthma or COPD, use your action plan as well as this page.
How long should a cough last?
Most coughs are viral, often from a cold or flu, and settle within about three weeks. NHS advice is that a cough usually clears on its own within three to four weeks. There is usually no need to see a GP in that window if you are otherwise well. A cough lasting more than three weeks should be checked.
The cough often outlasts the sore throat and fever. Airways stay irritable while they heal. That lingering phase is miserable and still usually viral. Rest and fluids do more than a hunt for a stronger bottle.
A cough that keeps returning, or never really leaves, is a different story from a single winter virus. So is a cough in someone having chemotherapy, or living with poorly controlled diabetes — NHS lists a weakened immune system as a reason to see a GP sooner.
Whooping-cough-type spasms, a cough after a choking episode, or a cough in a baby who is not feeding are not “wait three weeks” problems. Use 111 or 999 depending on how hard they are working to breathe.
Does coloured mucus mean I need antibiotics?
No. Yellow or green mucus is common with viral infections and does not by itself mean you need antibiotics. NICE guidance on acute cough advises against routine antibiotics for most people. A GP may still prescribe them if they think you have a bacterial infection or you are at higher risk of complications.
GOV.UK advice from the old Public Health England campaign is the same: green phlegm or snot is not always a bacterial infection that needs antibiotics. Colour comes from cells in the mucus, not from a traffic-light system for prescriptions.
People with COPD are a partial exception: a change to green sputum can mean an infection in that group and should be assessed, using the plan you were given. Recurrent chest infections also need a GP, not another winter of leftover tablets.
How unwell you are matters more than the colour. Breathlessness, chest pain, confusion, coughing blood, or a cough that is rapidly worse are the prompts — not mustard versus lime.
What can I try at home or with a pharmacist?
Rest and drink fluids. Stay home if you have a high temperature or feel too unwell for normal activities. A pharmacist can advise on paracetamol or ibuprofen — follow the pack. Honey and lemon in warm water is sometimes used, but not honey for babies under one. Evidence for cough bottles is limited.
NHS pages also note that decongestants and cough medicines containing codeine will not stop your cough. Some cough medicines should not be given to children under 12. Ask the pharmacist rather than sharing an adult bottle.
Paracetamol or ibuprofen can ease aches and a high temperature if they are suitable for you. Pregnancy, stomach ulcers, some asthma, kidney, heart or liver problems are reasons to check first. Use the lowest amount that helps, for the shortest time, as the pack describes.
Stopping smoking helps a cough settle. That is treatment, not a lecture. If heartburn is the pattern — worse at night or after meals — see heartburn and acid reflux rather than buying a third linctus.
When should I see a GP — and when is it 999?
See a GP if a cough lasts more than three weeks, you lose weight without trying, or you have a weakened immune system. Ask for urgent GP or NHS 111 help if the cough is rapidly worse, you feel very unwell, you have chest pain, you struggle to breathe, or you cough up blood.
Call 999 for severe breathlessness, chest pain, or lips or face turning blue or grey. On brown or black skin, paleness or greyness can be easier to see on the palms. Do not drive yourself in a life-threatening emergency.
NICE suspected-cancer guidance is one reason GPs take a cough past three weeks, unexplained weight loss, and a lasting hoarse voice seriously. Most people with those symptoms do not have lung cancer. Checking is still the right door.
| What you notice | First sensible step | Skip this |
|---|---|---|
| Cough with a cold, under 3 weeks, otherwise coping | Self-care and a pharmacist if you want symptom relief | Antibiotics because mucus turned green |
| Cough lasting more than 3 weeks, weight loss, lasting voice change | GP | Another week of cough mixture as the only plan |
| Coughing up blood, rapidly worse, hard to breathe, very unwell | Urgent GP or NHS 111 | Waiting to see if it “breaks” overnight |
| Severe breathlessness, chest pain, blue lips | 999 | Driving yourself, or sitting in A&E without telling staff you are worse |
If shortness of breath is new and severe, treat the breathing, not the cough article.
Could it be a cold, asthma, COPD or something else?
A cough with a runny nose and sore throat often starts as a common cold. A cough with wheeze or breathlessness can be asthma, especially if it is worse at night or with exercise. In people with COPD, a change in cough or sputum can mean a flare. Do not delay 999 if breathing is severely difficult.
Bronchitis is often a viral chesty cough after a cold. Acid reflux can cause a dry cough at night. Hay fever can tickle the throat for weeks in season. Smoking maintains a cough for as long as you smoke.
None of those labels is a diagnosis you should give yourself while you are struggling to speak. Use your inhalers as prescribed if you have them. If they are not helping and breathing is getting worse, that is 111 or 999, not a new Google term.
A cough is rarely lung cancer. Rare is not never. The three-week rule, blood, weight loss, and voice change exist so that the rare cases still reach a GP.
Who is this page not for?
This page cannot diagnose pneumonia, whooping cough, or lung cancer. It is not for a child who is struggling to breathe — call 999. It is not a smoking-cessation programme, though stopping smoking helps a cough settle. If the main problem is tight chest pain spreading to the arm or jaw, use the chest pain page and call 999.
It is also the wrong page if you need a COVID or flu test for work, or a fit note. Those are GP or employer processes. If you only need to know which NHS building to use, see pharmacy, GP, 111 or A&E.
Parents: a child who is unresponsive, working hard to breathe, or has lips that look blue needs 999 without finishing a decision tree.
Common questions about cough
- How long should a cough last?
- A cough from a cold or another virus usually settles within about 3 weeks. NHS advice is that many coughs clear on their own within 3 to 4 weeks. There is usually no need to see a GP in that window if you are otherwise well. A cough lasting more than 3 weeks should be checked.
- Does green or yellow mucus mean I need antibiotics?
- No. Coloured mucus is common with viral infections and does not by itself mean you need antibiotics. NICE guidance on acute cough advises against routine antibiotics for most people. A GP may still prescribe them if they think you have a bacterial infection or you are at higher risk of complications.
- When should I call 999 for a cough?
- Call 999 if you have severe difficulty breathing, chest pain, or lips or face turning blue or grey. Do not drive yourself in that situation. Tight chest pain spreading to the arm, neck or jaw is a 999 call even if you also have a cough. Use the chest pain page if that is the main symptom.
- How can I ease a cough at home?
- Rest, drink fluids, and stay home if you have a high temperature or feel too unwell for normal activities. A pharmacist can advise on paracetamol or ibuprofen — follow the pack. Honey and lemon in warm water is sometimes used, but not honey for babies under one. Evidence that cough bottles stop a cough is limited.
- Could my cough be asthma or COPD?
- A cough with wheeze or breathlessness can be asthma, especially if it is worse at night or with exercise. In COPD, a change in cough or sputum can mean a flare and needs the plan you were given, or a GP if you have no plan. A runny nose and sore throat with a short cough is more often a common cold.
- When should I see a GP about a cough?
- See a GP if it lasts more than 3 weeks, you lose weight without trying, or you have a weakened immune system. Get urgent GP or 111 help if you cough up blood, feel very unwell, have chest pain, or find it hard to breathe. A lasting voice change also needs a GP, not another bottle of linctus.
- Should I take leftover antibiotics for a cough?
- No. Most coughs are viral, so leftover antibiotics will not help and can cause side effects and resistance. NICE and NHS advice is that antibiotics are not normally prescribed for coughs. A clinician decides if you need them. Do not start a previous course because the mucus turned green.