Cough: Common Causes and When to See a Doctor

Almost everyone coughs now and then. A cough is a reflex that helps clear the airways, and most of the time it is nothing to worry about. Still, a cough that lasts a long time or comes with other symptoms deserves attention. This article explains the common causes, what you can do at home, and when to see a doctor.

How long does a cough last?

The NHS says a cough will usually clear up on its own within 3 to 4 weeks. A cough that goes on for more than 3 weeks is treated as persistent and should be checked by a doctor.

Common causes of a cough

According to the NHS, colds and flu are the most common causes. Other causes include:

• Smoking
• Acid reflux
• Allergies, such as hay fever
• Infections such as bronchitis or COVID-19
• Mucus dripping down from the back of the nose

The NHS adds that a cough is rarely a sign of something serious, such as lung cancer. Because causes vary, a doctor is the right person to work out why a cough is lasting.

Looking after yourself at home

The NHS suggests these simple steps:

• Rest and drink plenty of fluids
• Stay at home and avoid other people if you have a high temperature or feel too unwell for normal activities
• Ask a pharmacist or doctor about safe pain or fever relief if you feel unwell
• Try a warm drink with lemon and honey for comfort. This is not suitable for babies under 1 year.

The NHS notes that the evidence that lemon and honey or herbal remedies ease a cough is limited. A pharmacist can suggest cough syrups or sweets, but the NHS says these may reduce coughing without stopping it. It also says decongestants and codeine-based cough medicines will not stop a cough. Always check with a pharmacist or doctor before using any medicine, especially for children, during pregnancy or if you take other medicines.

Do I need antibiotics?

The NHS says antibiotics are not normally prescribed for a cough. They are used only when there is a bacterial infection or a risk of complications. The CDC explains that antibiotics do not work on viruses, and that most chest colds (bronchitis) are caused by viruses. Taking antibiotics when they are not needed will not help you get better faster and can cause side effects. Your doctor will decide whether they are right for you.

What a doctor might do

If you see a doctor about a cough, the NHS says they may:

• Listen to your chest
• Take a sample of any mucus
• Arrange an X-ray, an allergy test or a lung function test
• Rarely, refer you to a specialist

When to see a doctor

The NHS advises seeing a doctor if:

• Your cough has lasted more than 3 weeks
• You are losing weight without a clear reason
• You have a weakened immune system, for example because of chemotherapy or diabetes

The NHS says to get urgent medical advice if:

• Your cough is severe, getting worse quickly, or you cannot stop coughing
• You feel very unwell
• You have chest pain
• The side of your neck is swollen and painful
• You have difficulty breathing
• You cough up blood

In an emergency, call your local emergency number (112 in India, 911 in the United States).

Practical tips

Quitting smoking and avoiding smoky places can help if smoke is a cause. If you notice your cough is worse at night, comes with a runny nose and sneezing, or follows a meal, mention this to your doctor, because it can point towards the cause. A simple note of when the cough happens, how long it has lasted and any other symptoms makes a doctor's visit more useful.

This article is for general education only and does not replace advice from a doctor who knows your health history.