Coughing is not a pleasant experience for all of us, but we need to understand that coughing, despite all the pain and discomfort it brings to us, is often a natural reaction of our body to keep our respiration system and airways healthy and clean. In the following, we will tell you how we cough and what are the reasons for coughing. 

What is coughing?

What are the causes for coughing?

Coughing as a symptom of some diseases

Different types of coughs

In what cases should we see a doctor?


What is coughing?

 When we use the term "respiratory tract" in this article, we mean all the way that the air travels from our nose and mouth to the bottom of our lungs. The nasopharynx, throat, larynx, vocal cords, trachea, and structures inside our lungs are all part of this airway.  

When a stimulus is placed at any part of this airway, it is sensed by the nerves in these areas. This sensation is carried to the medulla oblongata by the nerves which then get transferred to the brain. The center of the cough is in the brainstem. When a respiratory stimulus reaches this part of the brain, commands from this part are transmitted by the efferent nerves to different parts of our airway, which results in coughing.

 How are these commands result in coughing?

  • First, a deep inhale is ordered;
  • Then, the valve between the throat and the trachea, called the glottis, closes;
  • and finally, the diaphragm relaxes.

With these actions, the immense amount of air that had entered the lungs with that deep inhale will be trapped in the lungs between the closed glottis and the diaphragm, which in turn increases the pressure inside the chest. This high pressure narrows down the trachea. Now is the time for the brain to command muscles to contract. Through the muscles contraction, the air trapped in the lungs opens the gluteal valve with high pressure, exiting the body through the airway at high pressure and speed. this pressure causes irritants, dust, secretions, and contaminants to be expelled from the airway along the way.

What are the causes for coughing?

Our airways, especially from the throat down, are very sensitive to the presence of foreign objects, pollutants and stimuli. Even the lowest parts of our lungs are extremely sensitive to the inhalation of certain gases, such as chlorine and sulfur dioxide. So, as you can see, coughing, by itself, is a way our body is trying to protect us and keep our airway clean.

This air, which comes out with high pressure and speed, can expel any object that is stuck in our throat and airway saving us from suffocation. Some of the reasons which activate the reaction mechanism of cough are: 

  • Gastric acid reflux (GERD)
  • Presence of gastric secretions in the throat and larynx
  • Seasonal and general allergies to various allergens, irritants and environmental allergens
  • Air pollution (like the presence of irritating gases such as sulfur oxides, etc.)
  • Food and foreign objects trapped in the throat
  • Nasal secretions gathered in the throat


Coughing as a symptom of some diseases:

In addition to external stimuli, another factor that triggers the coughing is the inflammation of the airways. Any illness that causes inflammation and narrowing of the airways will be accompanied by a cough such as:

  • Viral infections causing colds
  • Sinusitis
  • Croup in children
  • Asthma
  • Cystic Fibrosis
  • Bronchitis
  • Bronchiectasis
  • Pneumonia
  • Lung Abscess
  • Sarcoidosis
  • Tuberculosis

 In addition to inflammation, any factor that puts pressure on the airways can also cause a cough reflex, such as Tumors and Sarcoidosis. Independent from all the above items, coughing can also be caused by the following reasons:

1. Heart failure: In this case, coughing occurs due to accumulation of liquid in tissues and edema of lungs.

2. High blood pressure medications from the families of ACE inhibitors, like Captopiril and Enalapril.


Different types of coughs:

Most physicians in general divide the cough into three categories based on cough prolongation:

 - An Acute Cough: Acute cough is when the coughing goes on for less than three weeks since the beginning of coughing. The common causes of acute coughs are:

- Virus causing infection within respirational systems

- Contact with stimulants and allergens

 - A Subacute Cough: Coughing that lasts for more than three and less than eight weeks. Post infectious cough is the most common cause of subacute coughs.

 - A Chronic Cough: Coughs that last more than eight weeks. The most common causes of chronic coughs are:

- Asthma

- Gastric reflux

- Chronic sinusitis

One of the most annoying coughs are those that occur after the cold or viral bronchitis and sometimes even last up to two months. these are mainly known as post infectious coughs that are usually followed by post-nasal secretions.


In what cases should we see a doctor?

If the cough is followed by any of these symptoms you should see your doctor:

- Shortness of breath

- Anorexia

- Weight loss

- Night sweats

- Bloody sputum

- Vomiting blood

Remember that a smoker who is accustomed to persistent coughing and sputum should also see a doctor if the nature of his or her cough has changed.




share this content in :
Address: 393 University Avenue,Suite 200,Toronto ON MG5 2M2,CANADA


Phone: 1(647)303 0740

All Rights Reserved � By MarsoClinic

Terms of Use