Indigenous Australians are members of one of the high-risk groups being urged to be tested for diabetes, during National Diabetes Awareness Week.
Greg Johnson from Diabetes Australia says people from Aboriginal, Torres Strait Islander, Chinese, Indian and Pacific Island backgrounds are more likely to get a condition which can lead to type-two diabetes.
Mr Johnson says people who are overweight, inactive, over 55 years of age or have a family history of diabetes are also at risk.
He says an estimated two million Australians have pre-diabetes, and about half of them do not know they have it.
He says those from high risk groups should be tested for diabetes annually.
"Type two diabetes is the commonest cause of diabetes. It makes up approximately 85 percent of all people with diabetes.
"It's a metabolic disorder essentially, where the body produces the hormone insulin, either not enough of it or you are not able to use it properly.
"We don't know what causes it and we don't why particular groups are at higher risk than others."