Asthma is a health condition in which the patient has difficulty in breathing and experiences shortness of breath. Asthma is derived from the Greek verb aazein, which means panting, and is a classic symptom of acute asthma. The most basic definition of asthma is a chronic inflammatory airway disease of the lungs that causes breathing difficulty.

Many experts agree that asthma is now a global epidemic and its incidence continues to grow primarily in developed countries. In the Western world, 1 in 13 adults and 1 in 8 children suffer from bronchial asthma. About 17 million people suffer from asthma in the United States and it is the most common chronic disease in children.

Asthma affects about 5% of individuals around the world (about 300 million individuals). In North America and Europe, it is the most common chronic disease affecting all age groups.

This is a chronic condition having no permanent cure. Treatment mainly aims to stop an acute attack and also prevent further attacks


The cause of an asthmatic attack is an autoimmune response of the body to an allergen, with which the body has come in contact. Several immune system processes are involved in its development. Asthma, therefore, is typically an allergic reaction. To understand allergy and its causes, you could refer to what is allergy and what causes it.

Due to the autoimmune response of the body to an allergen, the following happens:

  • The walls of the airway in the lungs (bronchi and bronchioles) thicken due to the inflammation of the overdeveloped mucus glands, which secrete more mucus.
  • There is a tightening of the smooth muscles of the airways, which causes them to narrow (bronchoconstriction)
  • Edema and swelling develop in the airways due to the inflammation of the bronchi and the bronchioles.

All the above factors cause the narrowing of the airways to the lungs causing obstruction to the airflow and difficulty in breathing.

Causes, Risk Factors, and Triggers

It’s not clear why some people develop asthma and others don’t. However, it’s believed that a combination of environmental and inherited factors is responsible.

Asthma attacks are triggered by exposure to certain elements. These vary from person to person, but the common substances that trigger an acute asthma attack are mentioned here.

There is evidence of a familial tendency or a hereditary (genetic) trait, which can predispose you to this health condition. First-degree relatives of asthmatic patients have a higher prevalence of bronchial asthma. Therefore, if your parent has asthma, you should take precautionary measures.

Trigger factors can include:

  • Exposure to certain pollutants in the environment
  • Dander from many animals such as cats, dogs, birds, horses, and other pet rodents
  • Dust mites
  • Pollen from trees and grasses
  • Exposure to cold and humid climates. Incidences of asthmatic attacks are more during rainy and cold climates.
  • Inhalation of certain incense aromas, smoke, cigarette smoke, etc.
  • Drugs such as Beta-blockers, antibiotics, and aspirin.
  • Mental stress
  • Common allergens are pollen, dust, mold, and smoke.
  • Certain foods, which commonly trigger asthmatic attacks are milk, peanuts, eggs, and seafood like shellfish, crabs, and lobster.
  • Certain bacterial and viral respiratory tract infections
  • Exercise in asthmatic patients can also trigger an acute asthma attack.

Risk factors

It is believed that a number of factors make you prone and increase your chances of developing asthma. They include:

  • Having a blood relative who suffers from asthma. A blood relative includes a parent, brother, sister, aunt, uncle, nephew, niece, and first cousin.
  • You suffer from another allergic condition, such as atopic dermatitis  or hay fever
  • You are obese
  • You smoke regularly
  • You are regularly exposed to secondhand smoke
  • You are exposed to exhaust fumes or other types of pollution
  • You are exposed to occupational factors such as chemicals used in farming and manufacturing where you breathe in chemical fumes, gases, dust, or other substances while working.

Symptoms, Signs, and Complications

Asthma symptoms vary in intensity and frequency from person to person. They can occur on exertion or even at rest.

Symptoms, when present, develop more at night and/or early morning. This is possibly due to lower temperatures and higher humidity during the night and early morning hours. Both these factors trigger an asthma attack.

Symptoms include:

  • Shortness of breath
  • Wheezing
  • Cough with or without sputum. Sputum tends to be white but can turn yellow or green if bacterial infection sets in.
  • Tightness in the chest
  • The rapid rate of breathing
  • Chest pain in a severe attack
  • Many people with asthma also suffer from allergic rhinitis.
  • Common symptoms in infancy and early childhood include wheezing, persistent cough, and cold.

Signs (what the doctor notices)

  • Rapid heart rate and pulse
  • Rhonchi (typical whistle-like sounds) are heard through the stethoscope on the chest.
  • In severe attacks, you will develop pale and cold skin, sweating, and bluish discoloration of the nails.


  • In chronic asthma, which has developed in childhood, the thorax undergoes certain developmental changes due to the extra effort required to breathe. The sternum caves in and the ribs lift upward and forward. This is called the pigeon chest.
  • Status Asthamaticus is a condition where the patient’s symptoms fail to respond to the usual line of treatment. It develops in chronic asthma patients. It is a life-threatening complication and immediate hospitalization and emergency treatment are required.