Diagnosing asthma can be difficult. Asthma signs and symptoms can range from mild to very severe and are often similar to those of other conditions, including emphysema, early heart failure, or a type of vocal cord dysfunction. In order to rule out other conditions, you'll usually undergo a complete physical exam.
Your provider will probably ask if you've experienced periods of coughing, wheezing, shortness of breath, or chest tightness that come on suddenly, occur often, or seem to happen during certain times of the year or season. You'll also be asked about colds that seem to "go to the chest" or take more than 10 days to get over, medicines you may have used to help your breathing, your family history of asthma and allergies, and things that seem to cause or increase your symptoms.
Your provider will then listen to your breathing and look for signs of asthma or allergies. Often a device called a spirometer will be used to check how your lungs are working. The test is called spirometry, and it measures how much air you can blow out of your lungs after taking a deep breath, and how fast you can do it. The results will be lower than normal if your airways are inflamed and narrowed, or if the muscles around your airways have tightened up.
As part of the spirometry test, your provider may give you a medicine that helps open narrowed airways to see if the medication changes or improves your test results.
If your spirometry results are normal but you have asthma symptoms, your provider may suggest that you have additional tests to determine the cause of your symptoms. These other tests may include:
- Allergy testing to determine which, if any, allergens affect you
- A peak airflow test, in which you use a peak flow meter every day for one to two weeks to check your breathing. A peak flow meter is a hand-held device that helps you monitor how well you are breathing.
- A test to see how your airways react to exercise
- Tests to see if you have gastroesophageal reflux disease, or GERD
- A test to see if you have sinus disease, or
- Other tests, such as a chest x-ray or an electrocardiogram, may be needed to rule out other lung or heart diseases that could be causing your symptoms.