Diagnosing Asthma

Once you’ve made your appointment, our specialists will evaluate your symptoms, complete your medical history, and conduct a physical exam. We may conduct one of the following tests to determine if you have asthma and if yes, its level of severity.

Pulmonary Function Tests

Pulmonary function tests assess your lung function or capacity. The tests involve normal and deep breaths as well as breathing out as hard as you can into a tube. Occasionally you will be asked to briefly hold your breath. Your physician will use the results together with your symptoms to assess the severity of your asthma. These tests are typically repeated over time to evaluate your response to treatment. Some of these tests are highly specialized and will provide information about your small airways compared to your large airways. In addition, a simple breathing test called fraction of exhaled nitric oxide (FeNO) will help assess how much allergic inflammation you have in your lungs. Results of such studies will help your physician design a better treatment plan for you.

Methacholine Challenge Test

This test is used to establish a diagnosis of hyperreactive airways, one of the features of asthma. We will ask you to breathe through your mouth a mist of placebo (salt water) first and then increasing amounts of the drug Methacholine. After each mist you breathe in, we will measure your lung function. The test will end when you experience significant asthma symptoms (such as wheezing, coughing, and/or chest tightness) and/or your lung function has decreased and/or you have received the highest dose of Methacholine that we give. At the end of the test, you will receive a bronchodilator medication, which will relieve any symptoms that you may have.

Allergy Skin Testing

Allergy skin testing is performed to assess your sensitivity to multiple common allergens including grasses, trees, molds, dust mites, and animal dander. The test involves placing a drop of various allergy solutions on the inner surface of your forearm, lightly pricking the skin under each drop, and measuring the swelling or redness that may occur. Your doctor may also choose to evaluate you for allergies by a simple blood test. These results are important since patients with allergic asthma may receive a different treatment approach than those patients without allergies.