What to Expect - Asthma

What to Expect
Patient Guide: Asthma

There are several tests and asthma labs used to make a proper diagnosis and monitor your ongoing condition. Below are listed the most common asthma tests and labs ordered, why you need them, and what they can tell you about your condition.

Asthma Tests

Test Why Test? What Happens? What is Normal/Abnormal?
Lung Function Test (Spirometry) Measures the amount (volume) and/or speed (flow) of air that can be inhaled and exhaled in the lungs In this test, the patient performs several hard breathes into a machine. Accurate measurement is dependent upon the patient's performing the appropriate maneuver properly. Very difficult to perform in children.
Methacholine Challenge Test Methacholine is a known asthma trigger. Patient is given a device to breathe in the methacholine. Any spasm or narrowing of the airway can indicate asthma.
Chest X-Ray Rules out any other cause of blockage/narrowing of the bronchi from infection to fracture This is a non-invasive test. A picture is taken of the chest and lungs. Asthma cannot be detected through X-ray, but determines other abnormal conditions of the lung, chest and/or heart.
Strip Test Tests the pH of the digestive system to rule out gastroesophageal reflux disease (GERD)/heart burn The pH procedure is done with a thin, plastic tube with a sensor that measures the amount of acid backing up into the esophagus. pH is measured on a 1 to 14 spectrum. Normal range is between 5 to 8.
CT Scan of the Sinus Looks at the inflammatory conditions and fluid levels in the sinus This noninvasive medical test takes a picture of the bones, soft tissues and blood vessels. A clear sinus rules out sinusitis.
Asthma Labs
Name Why Test? Normal Range
Blood Test Immunoglobulin IgE, eosinophils IgE and Eosinophils are antibodies. If asthma is due to an allergy, the level of these antibodies will be raised. IgE - 4.2-595 U/mLEosinophil - 0 - 450 /µL