To get a proper asthma diagnosis, your doctor has access to several tools. The physical exam, personal and medical history, and lung function tests work together to help your doctor find out what's happening in your airways.
There are several types of lung function tests. If your doctor wants to see how sensitive your lungs are, they may have you do a provocation (proh-voh-KA-shun) test. It is also called a challenge or a trigger test.
A provocation test can help your doctor confirm asthma or even rule it out if other tests don't show clear results.
The most common types of provocation tests are:
- Irritant challenge
- Exercise challenge
- Methacholine (meth-uh-koh-leen) challenge
When doing a provocation test, you will also take a spirometry test before and after to see if your lung function changes.
During an irritant challenge, you are exposed to a trigger like a chemical, scent or smoke to see how your airways react.
If your doctor thinks you have exercise-induced bronchoconstriction (EIB), they might may test you using an exercise challenge. They will monitor your heart and breathing while you run on a treadmill.
The methacholine challenge is often used to rule out asthma. Your doctor may use this type of test if you aren't responding to asthma treatment.
There are other conditions that have symptoms similar to asthma. Some conditions that mimic asthma are:
- Heart failure
- Pulmonary embolism
- Chronic Obstructive Pulmonary Disease (emphysema or chronic bronchitis)
During this test, your doctor will have you inhale a drug called methacholine. If you have asthma, your airways will tighten with low doses. That can confirm asthma. If your airways do not tighten with a low dose, you may have another condition. It's important to make sure what condition you have so you get the right treatment.