OVERDIAGNOSIS of diseases and disorders causes harm and wastes millions of dollars on unncessary treatment, an Australian researcher says.

Advances in screening technology were a major contributor to detecting abnormalities that would not have caused symptoms, the article's authors including Bond University's Ray Moynihan wrote.

The trend towards overdiagnosis posed a significant risk to individuals' health, with estimates about $200 billion is spent every year in the US on unnecessary care, an article published in the British Medical Journal (BMJ) on Wednesday said.

Mr Moynihan said screening the healthy population was a double-edged sword.

While it made sense to detect and treat disease early, there was also a risk of labelling people as sick and unnecessarily treating individuals, he said.

 "We are now seeing evidence that this is happening in many conditions, particularly in cancer, and particularly in breast and prostate cancer," Mr Moynihan told AAP.

The article cited international research, published in the BMJ in 2009, which concluded about one third of all detected breast cancers may be overdiagnosed.

Canadian research suggested about 30% of those diagnosed with asthma did not have the respiratory disease.

Studies also showed chronic kidney disease, gestational diabetes, and high blood pressure and cholesterol had also been overdiagnosed.

Conditions like ADHD were also the subject of much debate about overdiagnosis, the authors wrote.

"This is not about trying to scare people away from valuable medical interventions," Mr Moynihan said.

"It is about saying we need to be more cautious when we are offering tests or treatments to healthy people.

"We seem to be in an age where we hand out diagnoses like lollies in the same way that in some instances we hand out medications like lollies."

Other factors driving overdiagnosis were good intentions fuelled by the fear of missing early signs of disease, the authors wrote.

But commercial and professional vested interests also played a part.

Resources now spent on overdiagnosing could be better used to treat or prevent genuine illness, the article said.

Early screening of prostate cancer has been in the headlines in the past week after the US Preventive Services Task Force advised men against taking the blood tests.

Cancer Council Australia chief executive Ian Olver said overdiagnosis would occur to some extent with early detection.