Q: Why do I cough when I have a respiratory infection? Is there a benefit or should I suppress it?
A: A cough is one way the body protects the airway so we can breathe and exchange carbon dioxide (bad air) for oxygen (good air).
Whether moving mucus which can block the airway or caused by an irritant, a cough can be beneficial. It is one of the primary symptoms of COVID-19 along with fever and shortness of breath.
However, prolonged coughing can cause other problems. Though most acute coughs last on average less than 18 days, don’t wait that long to seek medical care. A cough has the potential to spread disease or damage other organ systems.
Coughing is protective. It keeps the airway clear for the best possible gas exchange. Without coughing, we would succumb to conditions as common as colds, allergies, and aspirating liquids while laughing. Who hasn’t done that?
There are three ways that a cough is generated: inside the lungs, from other systems in the body, and from the brain. And there are many conditions and medications that can result in a chronic cough. We can cover those at another time. Today, let’s focus on acute, short-term coughs like those caused by irritants and infections.
In the lungs, there are two branches of the vagus nerve that sense the stimuli that cause irritation. One branch of the nerve senses chemical related stimuli. The other branch senses mechanical stimuli. Both branches send a message to the brain to cough. In 1954, Widdicombe reported additional cough receptors in the trachea and main-stem of the lungs. Remember when your elders told you to raise your arms in the air during a coughing fit? Well, they were right. Raising your arms eases the stimulation of the Widdicombe cough receptors in the airway.
Other areas of the body can initiate a cough too. In fewer than 5% of people, a branch of the vagus nerve in the ear can stimulate a cough. Although the mechanism is not entirely understood, the pathways in the nose, pharynx, and esophagus that stimulate coughing have been noted with conditions like colds, post-nasal drip, food, and high air pressure.
Popular over-the-counter cough suppressants work on the area of the brain that receives the message to cough from the lungs, ears, nose, pharynx, and esophagus. Recent studies show that those medicines do more to make us feel good than they do to suppress cough. Natural remedies to suppress cough primarily work as anti-inflammatories to decrease the stimulation of the nerves that carry the message to the brain.
Coughing to clear the airway is protective. However, prolonged cough can cause a host of problems such as:
1. Muscular pain
2. Cracked ribs
3. Damage to small blood vessels in vulnerable tissues like eyes, anus, and skin.
4. Rupture of the diaphragm
5. Abdominal hernia
6. Tissue damage in the throat
7. Coughing up blood
Each condition can be serious. Seek medical attention immediately if you experience any of them as a result of coughing or if a cough persists for more than a week. With your help, your clinician can determine if you have pneumonia, a collapsed lung, or other problems manifested through cough. And of course, don’t forget to cough into your elbow to prevent the spread of germs.