Asthma should not be diagnosed on symptoms alone, with a new study showing a concerning number of adults are being misdiagnosed with the lung disease.
A Canadian study published in the Journal of American Medical Assosiation found one in three adults (33 per cent) recently diagnosed with asthma by their physician did not have active, or symptomatic, asthma when evaluated using spirometry and serial bronchial challenge.
More than 90 per cent of these patients were able to stop taking their asthma medications without harm.
Worryingly, the study also found that doctors often did not order the tests needed to confirm asthma diagnosis. Instead they based their diagnosis solely on the patient's symptoms and their own observations.
Asthma Australia CEO Michele Goldman says misdiagnosis is not surprising but the large number of people who have been wrongly diagnosed in this study is.
She says it's concerning to think people could be taking medications when they don't need it.
"Apart from the side effects the individual might be experiencing there's also the costs to both themself and the health care system," Ms Goldman said.
The study looked at 613 randomly selected patients from 10 Canadian cities diagnosed with asthma in the last five years. After a series of detailed breathing tests followed by consultation with a lung specialist, asthma was ruled out in a third of these patients.
It was also found that in 49 per cent of these cases, physicians had not ordered the airflow tests required by medical guidelines.
When these patients were re-diagnosed, most had minor conditions like allergies or heartburn, and 28 per cent had nothing wrong with them at all.
Two per cent had serious conditions like pulmonary hypertension or heart disease that had been misdiagnosed as asthma, and went on to receive proper treatment.
Asthma Australia says it's critical doctors order the specific lung function tests and warns a diagnoses just based on symptoms is not reliable.
Breathlessness, wheezing, persistent cough or tightness in the chest aren't unique to asthma, they are also common in other conditions like heart disease and anxiety.
If you are concerned that you have asthma symptoms check with your doctor and ask for a lung function test, advises Ms Goldman.
Whether its misdiagnosis or underdiagnosis, which is a problem in Australia, it's important people are being treated appropriately and getting the protection from their preventer medication rather than risking what could be a fatal asthma attack.
"Over 400 people still die from asthma each year in Australia," Ms Goldman warned.
Asthma is a long-term inflammatory disease of the airways of the lungs but does change over time as well, so it's really important that patients get regular reviews with their GPs, says Ms Goldman.
