Cough
Productive and Non-Productive Coughs
Your body keeps its airways clear of mucus and foreign objects by coughing. A cough causes the muscles in the chest and diaphragm to contract while closing off the throat. This builds up pressure in the lungs, allowing them to expel air with great force. The force of this air then pushes the mucus and foreign bodies up through the trachea. This is a mostly involuntary reflex and is part of your body's natural defense against illness.
When you're sick, your body produces more mucus than normal, which is responsible for triggering a cough. Coughs can also be caused by irritation in the throat caused by allergies or environmental irritants. Depending on their cause, coughs will have different qualities:
Productive coughs, or "wet" coughs, are those that cause you to cough up phlegm. This sputum could come from the back of your throat, or it might come from your lungs. Productive coughs can be caused by many things including bacterial infections, viral illnesses and even acid reflux.
Nonproductive coughs, or "dry" coughs, do not produce sputum. These hacking coughs are often persistent and can last a long time. They might be caused by allergies, environmental irritants, asthma, or other similar conditions.
Over-the-counter and prescription cough medicines can work to suppress coughing. This enables patients to sleep if coughing is disrupting their rest, and it can give some relief to the muscles responsible for coughing. It's best, however, to avoid cough suppressants when possible for productive coughs as coughing will help clear the excess mucus and help the body overcome infection. For this purpose, commercial cough expectorants are available to encourage coughs to be more productive to lessen the duration of the illness.
Coughing is a symptom of many respiratory diseases, and its duration and severity can hint at the underlying cause. In most cases, mild coughs are caused by a cold, the flu or seasonal allergies. More severe coughs could be indicative of a more serious respiratory infection, like bronchitis or whooping cough. If your coughing is persistent and long-lasting, or if its severity is making it difficult to breathe, it's important to get medical care to address the cough's root cause.