What is a cough? — A cough is an important reflex that helps clear out the body's airways (the trachea and bronchi, which are the tubes that carry air within the lungs). Coughing helps keep people from breathing things into the airways and lungs that could cause problems (figure 1).

It is normal for people to cough once in a while. But sometimes, a cough is a symptom of an illness or condition.

Some coughs are called "dry" coughs, because they don't bring up mucus (phlegm). Other coughs are called "wet" or "productive" coughs, because they do bring up mucus. Some coughs are mild and don't cause serious problems. Other coughs are severe and can cause trouble breathing.

What causes a cough? — In adults, common causes of a cough include:

●Viral infections – These include the common cold, the flu, and COVID-19. Usually, cough caused by a viral infection will only last for a week or 2, but sometimes it can last for longer.

●Smoking cigarettes or vaping

●Postnasal drip – Postnasal drip is when mucus from the nose drips down or flows along the back of the throat. Postnasal drip can happen when people have:

•A cold

•Allergies

•A sinus infection – The sinuses are hollow spaces in the bones of the face that open into the nose (figure 2).

●Lung conditions, like asthma and chronic obstructive pulmonary disease (COPD) – These conditions can make it hard to breathe. COPD is usually caused by smoking.

●Acid reflux – Acid reflux is when the acid that is normally in your stomach backs up into your esophagus (the tube that carries food from your mouth to your stomach).

●A side effect from blood pressure medicines called "ACE inhibitors"

Should I call my doctor or nurse? — Call your doctor or nurse if you live in an area where people have coronavirus disease 2019 (COVID-19). They will ask you questions about your symptoms and whether you might be at risk. They can also tell you if you should get tested for the virus.

You should also call your doctor or nurse right away if:

●You have trouble breathing or noisy breathing (wheezing).

●You have a fever or chest pain.

●You cough up blood, or yellow or green mucus.

●You cough so hard that it makes you vomit.

●Your cough gets worse or lasts longer than 10 days.

●You have a cough and have lost weight without trying.

Will I need tests? — Maybe. To figure out the cause of your cough, your doctor or nurse will talk with you and do an exam. Based on your symptoms and other factors, they might decide that you need tests. These might include:

●A swab from your inside your nose – This can be tested for the virus that causes COVID-19.

●A chest X-ray

●Breathing tests – Breathing tests involve breathing hard into a tube. These tests show how the lungs are working.

●Allergy skin tests to find out what you're allergic to – For a skin test, the doctor puts a drop of the substance you might be allergic to on your skin and makes a tiny prick in the skin. Then they will watch your skin to see if it gets red and bumpy.

●A CT scan of your chest or sinuses – A CT scan is an imaging test that creates pictures of the inside of the body.

●Lab tests on a sample of the mucus you cough up

●Using a "scope" to look inside your nose, sinuses, airway, or lungs

●Tests to check for acid reflux – These usually involve having a thin tube put in your mouth and down into your esophagus.

Is there anything I can do on my own to get rid of my cough? — Yes. To help get rid of your cough, you can:

●Use a humidifier in your bedroom (if your cough is from a cold)

●Use an over-the-counter cough medicine, or suck on cough drops or hard candy

●Stop smoking, if you smoke

●If you have allergies, avoid the things you are allergic to (like pollen, dust, animals, or mold)

If you have acid reflux, your doctor or nurse will tell you which lifestyle changes can help reduce symptoms.

How is a cough treated? — Treatment depends on the cause of your cough. For example:

●Some infections are treated with antibiotic medicines. If an infection is caused by bacteria, doctors can treat it with antibiotics. If an infection is caused by the flu virus, a different medicine might help. If the infection is caused by another virus (such as the common cold), antibiotics will not help.

●Postnasal drip is treated with different kinds of medicines that can come as a pill or nose spray.

●Asthma and COPD are usually treated with medicines that people breathe into their lungs (called "inhaler medicines").

●Acid reflux can be treated with medicine to reduce or block stomach acid.

●If you have a cough as a side effect from an ACE inhibitor, your doctor can switch your medicine.

If the cause of your cough is not clear, your doctor might prescribe medicine to make your cough less severe. But these medicines have side effects, and doctors usually recommend them only if nothing else has worked.

More on this topic

Patient education: Cough, runny nose, and the common cold (The Basics)
Patient education: Acute bronchitis (The Basics)
Patient education: Chronic obstructive pulmonary disease (COPD) (The Basics)
Patient education: Acid reflux and gastroesophageal reflux disease in adults (The Basics)
Patient education: Asthma in adults (The Basics)
Patient education: Pneumonia in adults (The Basics)
Patient education: Side effects from medicines (The Basics)
Patient education: Whooping cough (The Basics)
Patient education: Seasonal allergies in adults (The Basics)
Patient education: Sinusitis in adults (The Basics)
Patient education: Quitting smoking (The Basics)
Patient education: Coughing up blood (The Basics)
Patient education: Bronchiectasis in adults (The Basics)
Patient education: COVID-19 overview (The Basics)

Patient education: Chronic cough in adults (Beyond the Basics)
Patient education: Gastroesophageal reflux disease in adults (Beyond the Basics)
Patient education: Chronic obstructive pulmonary disease (COPD) (Beyond the Basics)
Patient education: Pneumonia in adults (Beyond the Basics)
Patient education: Quitting smoking (Beyond the Basics)