Diagnosing asthma may be a difficult task at times for doctors, because this disease has many symptoms that mimic other pulmonary diseases. The first step doctors take to determine whether a patient has asthma is to take a medical history as well as family history of the patient. The doctor will be most interested in knowing the types and severity of the patient's breathing problems. Besides the medical history, the doctor will ask about what types of environmental allergens the patient might be exposed to including pet dander, dust mites, and pollen.

After a patient history is completed, several tests can be conducted to determine how well the lungs are functioning. Most of these tests measure the amount of air a patient can breathe in and exhale. Other tests measure the changes in a patients ability to efficiently breathe in and out.

Medical History

During your examination, the doctor will as about your...

Current Health. Symptoms of asthma include, but are not limited to, wheezing, shortness of breath, coughing, chest pain, and mucus in the airway.
Personal Health History. A history of eczema or allergies increases the likelihood of asthma.
Family Health History. If other close relatives have asthma, allergies, or eczema, the likelihood of the patient having asthma increases.
Environmental Irritants. A variety of allergens may induce an asthma attack. Knowing what allergens the patient is exposed to could help determine whether the asthma can be controlled without medication.

Pulmonary Function Tests

Spirometry -- In this diagnostic test, the patient is asked to breathe into a mouthpiece which is attached to a recording device known as a spirometer. The device measures how much air the patient can exhale at one time.

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Peak Expiratory Flow Test -- To determine the maximum rate at which the patient can expel air from the lungs, the patients exhales as hard as they can into a handheld device known as a peak flow meter

Methacholine Challenge Test -- In this diagnostic test, methacholine is inhaled into the lungs. Methacholine causes the airways to constrict of asthma is present. If lung function decreases by 20% as a result of the administration of methacholine, asthma is diagnosed.

Other Useful Diagnostic Tests

Chest X-Ray
Allergen skin tests
Gastroesophageal reflux assessment
Sinus X-Ray