It is difficult to establish the diagnosis of Asthma in the laboratory, for no single test is conclusive.
To differentiate other conditions like Bronchitis or COPD, the physician needs to evaluate and diagnose based on a detailed case history and clinical findings of the patient.
In children below 5 years, diagnosis of Asthma may be difficult. In such cases, inquiry about family history of Asthma, signs and symptoms or reaction to particular allergen or food substance is important.
Lung Function Tests are done to establish diagnosis of Asthma.
Spirometry: A device known as spirometer is use to measure the breathing capacity of the lungs.
Peak expiratory flow: It is done to check how well our lungs are functioning. In this test, patient is instructed to forcefully exhale out air in a tube to review the expiratory capacity of the lungs.
Allergy test: Allergens are injected into the skin in minute quantities to know if there is any underlying allergic tendency in the body.
Imaging: A chest X-ray or computerized tomography (CT) scan of lungs and sinuses can be done to identify any other structural abnormalities or to rule out other similar conditions.
Provocative testing for exercise: Here, the patient is asked to undertake certain vigorous physical activities and amount of airflow obstruction before and after exercise is measured.