Why Do We Cough? Causes and Prevention

Why do we cough? Coughing is one of our defense mechanisms to get rid of foreign particles that enter our respiratory system. Sometimes, it may be due to serious problems, such as infections or diseases.
Why Do We Cough? Causes and Prevention

Last update: 06 March, 2020

Why do we cough?

Believe it or not, coughing is a common symptom in all mammals. We’ve all coughed at some point in life. In fact, we know that 23% of people cough when they wake up in the morning, even if they don’t smoke. Likewise, we know that adults get about two to three colds per year and that there’s coughing in 75% of cases. Estimates indicate that 13% of people cough chronically, even when they don’t have a cold.

A cough is a reflex that could easily be due to disease, although it isn’t most of the time. In principle, it’s just a mechanism to expel irritating substances from our respiratory tract. In this article, we’ll take a closer look at this interesting bodily function and why it happens.

Why do we cough?

The first thing to be clear about is that coughing is one of our body’s defense mechanisms against external agents that may be harmful. We cough to clear our airways and to expel particles and foreign bodies.

Coughing is a sudden and explosive maneuver. This maneuver happens in three fast stages. In the first one, the glottis opens when we breathe in. In the second phase, there’s a contraction of the respiratory muscles. Finally, in the third phase, we expel the air retained in our lungs with an abrupt opening of the glottis.

The cough receptors are located mainly in the lower airway, which includes the larynx, trachea, and bronchi. They’re also in the nose in our sinuses, ear canal, pleura, diaphragm, and even in our pericardium and stomach.

A woman coughing.
Coughing is a defense mechanism and it doesn’t indicate a disease or infection for the most part.

Types of cough

There are several types of cough and only some of them are a reason to seek medical advice. In principle, coughs are first classified as productive or nonproductive.

A cough is productive when we expel phlegm or mucus, and this type of cough deserves medical attention. In contrast, a nonproductive cough is a dry cough in which no mucus is expelled. It causes itching, irritation and, often, a sore throat. There’s a third modality known as “fake dry.” There’s mucus in this one but we can’t expel it completely.

Based on the duration, a cough can also be classified as acute or chronic. It’s acute when its duration doesn’t exceed three weeks. Similarly, it’s chronic when it lasts more than 3 or 4 weeks. The latter is usually accompanied by irritation in the trachea or larynx.

Finally, there are whooping and psychogenic coughs. The first is violent, very contagious and quite dangerous in infants under 6 months. The second one is a type of psychosomatic cough, which usually appears when a person is very nervous.

Coughing is a common symptom that can be due to many causes. Most of the time it isn’t a serious problem and disappears by itself. However, it’s best to consult a doctor if it’s severe or is accompanied by other symptoms.

Next, we’ll tell you the main reasons why we cough.

Environmental stimuli

An environment with a lot of smoke or dust or mites usually leads to coughing attacks. It may be an allergy if it’s persistent, be it permanent or seasonal. Sudden temperature changes also lead to coughing.

Inflammatory processes

When the airways become inflamed, they impede the passage of air and can lead to coughing and pain. This occurs when there are common diseases such as the common cold or the flu. It also occurs in diseases such as bronchitis, pneumonia, fibrosis, asthma, lung cancer, etc.

Bronchitis, asthma and other respiratory diseases are a leading cause of coughing.

Other reasons why we cough

We might cough due to conditions of the nose, throat, ear and ear canal, or due to gastroesophageal reflux. A cough that worsens considerably at bedtime may be a sign of congestive heart failure.

A doctor wondering why do we cough.


Also, coughing is a side effect of certain medications such as angiotensin-converting enzyme (ACEI) inhibitors, which are often used to treat hypertension.


Finally, it’s common for those who smoke tobacco or anything else to have a recurrent cough. Keep in mind this isn’t healthy, even though it happens every day. Consult your doctor if you’ve been coughing for a long period.

Finally, we must mention that coughing can be due to psychogenic factors such as anxiety and nervousness.

Consult your doctor with any questions you might have.

It might interest you...
The Causes of Chest Pain When Coughing
Step To Health
Read it in Step To Health
The Causes of Chest Pain When Coughing

Chest pain when coughing is a very common symptom in people who suffer from certain respiratory system conditions.

  • Chung, K. F., & Pavord, I. D. (2008). Prevalence, pathogenesis, and causes of chronic cough. The Lancet. https://doi.org/10.1016/S0140-6736(08)60595-4
  • Dicpinigaitis, P. V., Colice, G. L., Goolsby, M. J., Rogg, G. I., Spector, S. L., & Winther, B. (2009). Acute cough: A diagnostic and therapeutic challenge. Cough. https://doi.org/10.1186/1745-9974-5-11
  • Martin, M. J., & Harrison, T. W. (2015, September 1). Causes of chronic productive cough: An approach to management. Respiratory Medicine. W.B. Saunders Ltd. https://doi.org/10.1016/j.rmed.2015.05.020
  • Holmes, R. L., & Fadden, C. T. (2004, May 1). Evaluation of the Patient with Chronic Cough. American Family Physician.
  • Kwon, N. H., Oh, M. J., Min, T. H., Lee, B. J., & Choi, D. C. (2006). Causes and clinical features of subacute cough. Chest129(5), 1142–1147. https://doi.org/10.1378/chest.129.5.1142