About this symptom
A cough is the body's way of clearing the throat and airways. It can be dry, or it can bring up mucus (phlegm). Most coughs come from a cold or flu and settle within a few weeks.
Other causes include smoking, acid reflux, allergies, mucus dripping down the throat, and chest infections. Some medicines can cause a dry cough, so tell the doctor what you take and do not stop them on your own. A long cough is rarely lung cancer, but it is checked for that, and in India always for tuberculosis (TB).
Possible causes
This is not a diagnosis. These are the causes doctors think about, with the ones that are most urgent to rule out first.
- TuberculosisA cough lasting two weeks or more, sometimes with blood in the phlegm, with fever in the evening, night sweats, weight loss and tiredness.Read about it
- PneumoniaCough with thick yellow or green phlegm, a high temperature, breathlessness, and chest pain that is worse when you breathe in or cough.Read about it
- Heart failureA cough that is worse at night or lying down, with breathlessness and swollen ankles or legs.Read about it
- COPDA long-lasting chesty cough with phlegm, breathlessness and frequent chest infections, mostly in people who smoke or used to smoke.Read about it
- AsthmaA cough with wheezing and tightness in the chest that comes and goes, and is often worse at night or in the early morning.Read about it
- BronchitisA cough that brings up phlegm after a cold, sometimes with a sore throat and a high temperature. It usually clears in about three weeks.Read about it
- Acid refluxA cough that keeps coming back along with heartburn, a burning feeling in the middle of the chest, often after meals or when lying down.Read about it
- Common coldThe most common cause: a cough with a blocked or runny nose and a sore throat, which settles within a few weeks.Read about it
When to get help
See a doctor soon if you have:
- A cough lasting more than two to three weeks
- Blood or blood-stained phlegm, even a few streaks (get this checked as soon as possible)
- Fever, night sweats or weight loss without trying
- Yellow or green phlegm, or chest pain when you breathe or cough
- A cough worse lying down, with breathlessness or swollen ankles
- A cough with diabetes, a weak immune system, or close contact with someone who has TB
In India, a cough of two weeks or more is treated as a possible sign of lung TB, and the national TB programme advises a check at a health facility. Some health services advise waiting three weeks. TB can be cured, and treatment is free at government facilities. A cough in a baby under three months needs a doctor straight away.
A short cough with a cold or flu, when you otherwise feel well, can usually be watched at home.
What you can do at home
Do
- Rest and drink plenty of fluids
- Honey and lemon in a warm drink may soothe the throat. Never give honey to a baby under one year
- Keep away from smoke and dust
- Take any asthma or lung medicines as advised
Do not
- Do not give cough or cold medicines to small children without asking a doctor or pharmacist
- Do not take unless a doctor prescribes them: they are not normally needed for a cough
- Do not wait weeks hoping a long cough will pass
Cough syrups and decongestants may help you cough less, but will not stop the cough or treat its cause.
What the doctor will do
The doctor will ask how long you have coughed, whether it is dry or brings up phlegm, and about fever, night sweats, weight loss, smoking, medicines and contact with anyone who has TB. They will listen to your chest.
Tests depend on the likely cause. They may include:
- A chest X-ray, and sometimes a
- A phlegm test, which also checks for TB
- A breathing test ()
- Blood tests, and sometimes tests for allergies or acid reflux
If TB is found, it is treated with for several months, and the whole course must be finished.
Myths and facts
Things people often say about this. Open each one to see what is true.
Myth“A cough that will not go away is just the weather or dust, and a cough syrup will fix it.”What is true?
Fact
A cough that lasts more than two to three weeks should be checked, because it can be a sign of TB or another lung problem. Cough syrups may help you cough less but will not stop the cough or treat its cause.
Myth“Antibiotics cure every cough.”What is true?
Fact
Most coughs come from a cold or flu, and antibiotics do not work on those. Doctors prescribe them only when there is a bacterial infection or a risk of complications.
Myth“TB always means coughing up blood, so a cough without blood is nothing to worry about.”What is true?
Fact
TB usually starts with a cough that does not go away, and blood in the phlegm is only one possible sign. Others are fever in the evening, night sweats, weight loss and tiredness. A cough of two weeks or more should be tested, with or without blood.
Myth“Cough syrup or a spoon of honey is the right way to settle a small child's cough.”What is true?
Fact
Cough and cold medicines are unlikely to work in young children and can cause serious side effects, so ask a doctor or pharmacist first. Honey must never be given to a baby under one year.
Questions to ask your doctor
Tick the ones you want answered and take them with you.
Common questions
How long is too long for a cough?
Most coughs from a cold or flu clear within a few weeks. A cough that lasts more than two to three weeks should be checked by a doctor. In India, a cough of two weeks or more is a reason to be tested for TB, so do not wait longer than that.
Is TB curable, and what does the treatment cost?
TB is curable with antibiotics, usually taken daily for several months. In India, treatment is free at government health facilities and at identified private and NGO facilities. It is important to finish the whole course even if you feel better, because stopping early is dangerous.
Do I need antibiotics for my cough?
Usually not. Most coughs come from colds and flu, which antibiotics do not treat. A doctor will prescribe them only if they find a bacterial infection or you are at risk of complications.
Why is my cough worse at night or when I lie down?
Asthma and acid reflux are often worse at night or when lying down. A cough that is worse lying flat, with breathlessness or swollen ankles, can also be a sign of heart trouble, so see a doctor soon.