Diagnostic Tests

Lung Function Test

Your doctor will use a test called spirometry (spi-ROM-eh-tre) to check how your lungs are working. This test measures how much air you can breathe in and out. It also measures how fast you can blow air out.

Your doctor may give you medicine and then retest you to see whether the results have improved.

If your test results are lower than normal and improve with the medicine, and if your medical history shows a pattern of asthma symptoms, your doctor will likely diagnose you with asthma.

Other Tests

Your doctor may recommend other tests if he or she needs more information to make a diagnosis. Other tests may include:

• Allergy testing to find out which allergens affect you, if any.
• A test to measure how sensitive your airways are. This is called a bronchoprovocation (brong-KO-prav-eh-KA-shun) test. Using spirometry, this test repeatedly measures your lung function during physical activity or after you receive increasing doses of cold air or a special chemical to breathe in.
• A test to show whether you have another condition with symptoms similar to asthma, such as reflux disease, vocal cord dysfunction, or sleep apnea.
• A chest x ray or an EKG (electrocardiogram). These tests will help find out whether a foreign object in your airways or another disease might be causing your symptoms.