Asthma overview and Definition

Asthma is a chronic condition of the respiratory system in which the airways get blocked and narrowed.the airways get swollen and may produce excess mucus resulting in breathing difficulties and couhing.


asthmatic is common among the people of age group above 65 years.


Asthma is described as an chronic infection which shows inflammation in the pulmonary airway and bronchial hyperresponsiveness to an allergen resulting in asthmatic conditions.inflammatory cells are accumulated in respiratory bronchioles.

Physiologically, allergen inhaled results in provocation of the inflammatory system of the respiratory system resulting in increased secreation of inflammatory mediators such as methacalmine and histamine. Release of histamine from the mast cells results in activation of the prostaglandins and leukotrienes.In addition to that cytokines are also released from the mast cells which leads to Increased vascular permeabilty,mucous secretion, bronchospasm, and wheezing.these are the signs of  EARLY ASTHMATIC ATTACK.

Triggering factors that results in  blockage of the pulmonary airway include cold air, exercise, viral upper respiratory infection, cigarette smoke, and respiratory allergens. Bronchial provocation with allergen induces a prompt early phase immunoglobulin E (IgE)-mediated decrease in bronchial airflow. Initially there is an increase in the leukocyte count in the pulmonary ares with help of CD4+ cells. The activated T-lymphocytes also direct the release of inflammatory mediators from eosinophils, mast cells, and lymphocytes. The cross-linkage of two IgE molecules by allergen causes mast cells to degranulate, releasing histamine, leukotrienes, and other mediators that perpetuate the airway inflammation. Histolopathology of the bronchial airway might shows  an inflammatory cells consisting of eosonophis,  mast cells, lymphocytes, monocytes and neutrophils.This is the sign of LATE ASTHMATIC ATTACK.

Routes of Transmission

Types of asthma: There are many types of asthma. Listed below are a few of the most common types:

  • Allergic Asthma
  • Bronchial asthma
  • Nocturnal Asthma
  • Occupational Asthma
  • Exercise-Induced Asthma
  • Alcohol induced asthma

Clinical signs & symptoms

 Difficulty in breathing

Wheezing cough


Rapid breathing

Difficulty in speech

Pressure on the chest

  • Risk factor: Having a blood relative with asthma, such as a parent or sibling
  • Having another allergic condition, such as atopic dermatitis — which causes red, itchy skin — or hay fever — which causes a runny nose, congestion and itchy eyes
  • Being overweight
  • Being a smoker
  • Exposure to secondhand smoke
  • Exposure to exhaust fumes or other types of pollution
  • Exposure to occupational triggers, such as chemicals used in farming, hairdressing and manufacturing

Differential Diagnosis

Diagnosis : It is easy to diagnose a patient with asthma. There are several tests available to detect the symptoms as asthma triggers. The common tests are spirometry, exhaled nitric oxide and challenge tests.

Spirometry is a type of lung function test that measures how hard a person can blow air out of their lungs. It can determine the level of obstruction in the airway. The test is performed using a machine called a spirometer.

Exhaled nitric oxide is a test that is performed by breathing into a hand-held machine. It then calculates the amount of nitric oxide present in the exhalation. Nitric oxide is produced inside the lungs and is an indicator of inflammation.

Challenge tests are tests which are performed if the other tests are not able to establish a diagnosis of asthma. Challenge tests are of two types – mannitol and methacholine. These agents, when inhaled, causes the airways to narrow only if asthma is present. The test involves the inhalation of these agents in the forms of aerosols or dry powders. If the lung function drops during the challenge, the individual is positive for asthma.

Other diagnostic procedures include:

  • Chest X-rays
  • Other lung function tests.
  • Allergy tests are recommended to detect the exact triggers.

General physical examinations for the functioning of the respiratory system.


it is a chronic illness and life long patient should be under medications.


Avoid coming into contact with the allerrgens

avoid humid climates.