How is it Diagnosed?
Asthma is a chronic inflammatory disease of the airways characterized by variable
airflow obstruction and bronchial hyperresponsiveness. Diagnosis involves clinical
assessment and pulmonary function tests.
History is central to diagnosis. Symptoms typically include wheezing, shortness of
breath, chest tightness, and cough—often worse at night or early morning and triggered
by allergens, exercise, cold air, or infections. A personal or family history of atopy
(eczema, allergic rhinitis) supports the diagnosis.
Physical examination during an acute episode may reveal wheezing, prolonged
expiration, and use of accessory muscles. However, between episodes, examination can
be normal.
Spirometry is the main diagnostic test. It measures forced expiratory volume in one
second (FEV₁) and forced vital capacity (FVC). A reduced FEV₁/FVC ratio that improves
significantly (>12% and >200 mL increase in FEV₁) after bronchodilator inhalation
confirms reversible airway obstruction.
Peak expiratory flow rate (PEFR) monitoring can help track variability in airway
obstruction. In children or those unable to perform spirometry, clinical diagnosis with
symptom pattern and treatment response may guide diagnosis.