A cough is an important reflex that helps protect the airways and lungs. Anything from fumes, dust, smoke, pollen, medication, or having a lung disease like asthma or COPD, may activate this reflex. Your throat and airways are equipped with cough receptors as well as a thin layer of mucus that coats and protects your airways. When you inhale a trigger, your cough receptors recognize the intruder, which gets stuck in the mucus lining your airways. Those cough receptors then send a message up to your brain which sends a signal back to the muscles of your chest wall and abdomen to rapidly and forcefully take a deep breath in and out to remove the trigger. Coughing can propel air and particles out of your lungs and throat at speeds close to 50 miles per hour, and this whole process is almost instantaneous and very effective. An occasional cough is a normal, healthy function of the body. But a persistent cough, one that doesn’t go away, is not normal. Any cough that lasts more than 8 weeks should be discussed with your doctor. And regardless of how long you had the cough, if it concerns you it should be brought to your doctor’s attention. Learn more about how your lungs function at Lung.org.

A cough is a spontaneous reflex. When things such as mucus, germs or dust irritate your throat and airways, your body automatically responds by coughing. Similar to other reflexes such as sneezing or blinking, coughing helps protect your body.

An occasional cough is a normal healthy function of your body. Your throat and airways are equipped with nerves that sense irritants and seek to dispel them. This response is almost instantaneous and very effective.

Throats and lungs normally produce a small amount of mucus to keep the airway moist and to have a thin covering layer that works as a protective barrier against irritants and germs you may breathe in. Some infrequent coughing helps mobilize mucus and has no damaging effects on your body. Coughing also allows for the rapid removal of any unwelcome particles you accidentally breathe in.

Cough Causes

These are common causes of acute cough – lasting less than two months:

Learn About Chronic Cough

Learn more about chronic cough and take the quiz to understand the possible causes of your cough.

Types of Cough

There are many different types of coughs with distinct characteristics that can help your doctor identify what underlying issue may be causing it. If a cough brings up phlegm or mucus it is called a productive cough and could suggest pneumonia, bronchitis or the flu. The color of the mucus can signal a more serious problem. You should see a doctor if your cough brings up yellowish-green phlegm or blood. A cough that doesn’t produce mucus is called a dry or nonproductive cough.

Acute cough is the least serious type of cough. It only lasts for three weeks or less and will most likely clear up on its own. This type of cough will not need medical attention. However, if the cough is accompanied by other symptoms such as fever, headache, drowsiness or shortness of breath it should be brought to a doctor’s attention. Coughs that make certain sounds, like whooping, wheezing or barking, may also signal a bigger problem.

Chronic coughs last longer than eight weeks and can be the sign of a more serious or chronic lung disease. Learn more about possible causes.

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Page last updated: July 30, 2025