Diagnosing Asthma
It can be difficult to diagnose asthma, because its symptoms often resemble those of other respiratory or heart disease. The diagnosis is usually based on a description of symptoms, the set of medical history, physical examination and the results of some laboratory tests. Among diagnostic tests, include pulmonary function, blood tests, chest x-rays and allergy tests.
The pulmonary function represents a series of tests to measure lung function. The most common is the spirometry test, which uses a device called a spirometer to measure the quantity and flow (flow) of air entering the respiratory tract, then emerging. Evaluation of peak expiratory flow is another test to measure lung function. Using a peak flow meter, measure the rate at which air is expelled from the lungs. You can use this device to monitor asthma at home.
The chest radiograph may help exclude other diseases.
Through blood tests, can detect high levels of white blood cells, indicating the presence of infection. You can also use a blood test known as the arterial blood gases to measure oxygen levels. If the doctor suspects that allergens trigger your asthma, it will use blood tests that measure antibody levels (IgE) to specific allergens.
The doctor may also ask to have allergy testing skin at the same time as testing for antibodies if it believes the allergen causes asthma.