Ask A Scientist

Why do we cough? 

Asked by: Magot Ajak
School: St. John the Evangelist School
Grade: 5
Teacher: Anu Rai
Hobbies/Interests: Basketball, drawing, video games, reading
Career Interest: Basketball player, scientist 

Answer from Angela C. Riley

Executive Director of Experiential Education

Research area: Clinical science, geriatric pharmacotherapy, health disparities, and health promotion Interests/hobbies: Traveling, reading, browsing the web

What a great question, Magot, especially as we approach the seasons where coughing seems to occur more frequently!

When we cough, our body is working to clear our throat or our respiratory system of items that should not be there. Our nervous and respiratory systems work together to prevent foreign items such as liquids, mucus and food particles from entering or remaining in our lungs and causing harm to our body.

Our lungs and trachea are the major parts of the respiratory system. Our nervous system is made up of sensors (receptors), nerves and the brain. The sensors feel changes/pressure/hurt all over the body and sends messages to our brain via the nerves. The sensors (receptors) in our respiratory tract sense when anything that is not a part of the normal tissue of the trachea or the lungs enters the area and rapidly send a message to the brain. The brain receives the message and then decides what needs to happen to protect the body. Immediately after the brain has received and interpreted the message from the sensor, it sends a message to our muscles, and the muscles move to protect our bodies from harm. 

When something foreign has entered the respiratory tract, the respiratory muscles quickly respond to the message sent from the brain. The respiratory muscles and muscles of the throat work together to cause a fast inhalation, closing/opening of the throat and forceful exhalation, which is the cough. This reflex action clears out anything that has entered and/or irritated the tissues in our respiratory system.

Although we know that a cough occurs because a foreign object enters the throat or respiratory tract, there are many causes for a cough, both long-term and short-term. One of the most common causes of a cough is due to a person being sick with a cold or the flu. This cough is typically short- term and can improve with medication. Our friends with asthma often have difficulty receiving air from the lungs, and they will cough too. However, if the asthma is treated by a healthcare professional, the cough should not happen as frequently. Smoking is another very common cause of coughing. Because the substance being smoked irritates the lungs, the body tries to protect itself by coughing out the irritants (which is why we should not smoke).

There are also diseases and medications that cause coughing in adults. Gastroesophageal reflux disease is one very common example of a disease that causes chronic cough. The ACE inhibutors used to treat high blood pressure are an example of medications that cause a dry cough in some patients.

Most importantly, when you have a cough that is extremely bothersome or lasts a long time, you must visit a healthcare practitioner. Your local pharmacist, nurse and physician will work together to help determine what is causing the cough and create a plan to eliminate or reduce the frequency and severity of your cough.

Last Updated: 3/1/17