How Asthma is Diagnosed
The severity of the disease varies widely from individual to individual, and can even vary in degree from day to day for a single person.
There are many different types of asthma, but all forms are diagnosed in the same way. The three keys to a diagnosis stem from factors like medical and family histories, physical exams, symptoms, and test results.
Because there are other conditions with symptoms similar to asthma, your doctor will want to narrow down your symptoms as much as possible to ensure an accurate diagnosis. He or she will ask your symptoms are, when they occur, and what causes your symptoms. For example, certain times of the year, certain places, or different times of day might affect your symptoms.
You should also inform your doctor of any other conditions you may have, no matter how unrelated they may seem. Things such as sleep apnea, eczema, acid reflux (or GERD), and even stress can contribute to asthma.
Once medical and family histories have been established, an actual physical exam will take place. The doctor will listen to you breathe and watch for any signs of wheezing. Wheezing, characterized by a scratchy or whistling sound, is the most common symptom of asthma. Runny noses, swollen nasal passages, and swollen airways are also common signs of asthma.
“The main things I look for when making an asthma diagnosis are things like recurrent wheezing, coughing, waking up at night, shortness of breath, and chest pain or tightness; particularly after exercise or in a pattern,” said Dr. Robert Strunk, professor of pediatrics at Washington University School of Medicine. “Some pediatricians are reluctant to call that asthma, but it needs to be treated as such.”
The doctor may order lung function testing to be done, depending on the patient’s age. This type of testing is especially difficult for children under the age of five. One device used for lung function testing is a spirometer. It measures the amount of air you can breathe in and out, and how fast the air actually is blown out.
Another device used in testing is a Peak Flow Meter, which measures the amount of air that flows out of the lungs. The patient forcefully blows into the device, and it calculates their optimal level of lung function. This information is helpful in order to create an Asthma Action Plan.
“I am cautious about testing with peak flow meters because they are effort-dependent. If a patient is already not feeling well, their [personal best peak flow measurement] number will be low. I rely more on symptoms than anything,” said Dr. Strunk.
If necessary, other, more in-depth testing can be performed, as well. Allergy tests, blood tests, and a “challenge test,” are all testing options. The challenge test measures how sensitive airways are during physical activity, after inhaling cold air, or after the chemical methacholine, which provokes narrowing of the airways, has been administered to the patient.
Once testing has been completed, medications will most likely be prescribed, and retesting will be scheduled for a later date. If the results of the retest have improved with the medications, you will most likely be diagnosed with asthma.