You probably either have asthma or know someone who does. Approximately 25 million people in the U.S. do, and, while the disease is usually quite manageable, it still can be scary, not to mention inconvenient: It’s not fun to suddenly have trouble breathing, or to have to worry about carrying an inhaler around with you.
But a study just published in JAMA suggests many people who are diagnosed with asthma don’t, in fact, have asthma. As Nicholas Bakalar of the New York Times reports, Canadian researchers recruited 613 men and women who had recently been given asthma diagnoses, and then “over four visits they gave them a series of drug challenges and spirometry, a physical test of breathing capacity, to confirm or rule out the disorder.”
“The researchers were able to rule out asthma in 203, or about a third of subjects, most of whom were taking asthma medicine,” writes Bakalar. As it turned out, a lot of them had been diagnosed on the basis of symptoms alone, which lead author Shawn D. Aaron told Bakalar shouldn’t count as sufficient evidence for a diagnosis. “If you have shortness of breath, wheeze or cough, you should suggest that the doctor order a spirometry test,” he said. “It’s a quick test with no risks or side effects that can predict asthma or other respiratory conditions.”
This sample was generated from random dialing, so there’s solid preliminary reason to think that such misdiagnoses are common. Assuming U.S. doctors make similar blunders, that could translate to millions of people who think they have asthma, but don’t. If you have asthma and have easy access to the doctor who diagnosed you, it might be worth asking him or her a few quick questions.