Dubbo is ranked number three on a new diabetes hot spot list, behind Blacktown with 3397 residents diagnosed with the chronic disease and Port Macquarie with 2473.

The figure for Dubbo is set to rise if residents heed the advice of Diabetes NSW to have a "really simple blood test covered by Medicare".

Its chief executive officer Sturt Eastwood suspects there "could be up to another 1000" residents unaware they have diabetes.

"We would suggest that 30 to 50 per cent of that number (2443) are walking around with Type 2 diabetes and don't know it," he said.

The Diabetes NSW figures were released on Sunday, the start of National Diabetes Week.

Statewide education and awareness activities throughout the week seek to support the one in four people in NSW living with or at risk of diabetes.

Diabetes NSW research suggests that "every 15 minutes someone in NSW is diagnosed with diabetes".

"Diabetes is a serious, progressive and complex condition with serious complications," Mr Eastwood said.

"There is no such thing as mild diabetes. All types of diabetes are serious and can lead to complications if not well managed.

"Diabetes can have a significant impact on quality of life and reduce life expectancy."

Diabetes NSW reports that Type 2 diabetes accounts for 85 to 90 per cent of all cases, including those in Dubbo.

People most at risk of it have a family history of the disease, ethnic background, are ageing and overweight.

Earlier this year a Heart Foundation report identified the Far West and Orana region of Western NSW as being second worse in the state for obesity and physical inactivity.

Mr Eastwood said Aboriginal people and Torres Strait Islanders "unfortunately are three times more likely to develop diabetes".

"That can play into the statistics," he said.

Diabetes NSW tells of the disease being a leading cause of blindness in working-age adults, and of kidney failure and dialysis.

It also increases the risk of heart attack and stroke by up to four times and is a major cause of limb amputations.

Mr Eastwood, who has Type 2 diabetes, said symptoms could include frequent urination leading to dehydration and thirst, constant hunger and tiredness.

"The tiredness is like after you have a very large Christmas dinner and need to lie down and have a nap," he said.

But the chief executive officer warned that not everyone experienced symptoms and complacency was unwise.

"There are fit and thin people with diabetes and hugely overweight people with no diabetes," he said.

Mr Eastwood said diagnosis and treatment could prevent life-changing complications and keep people out of hospital.

"In NSW alone hospitals spend about $160 million a year just dealing with the complications of diabetes," he said.

Mr Eastwood's message to Dubbo residents was two-fold.

"Follow the instructions of your GP and make diabetes part of your annual medical check," he said.

"It can be managed and we can test for it very easily these days.

"We want those other 1000 people to get onto treatment, because it will actually make a difference to their lives."

The diabetes hot spot list includes Tamworth and Orange, ranked eight and nine respectively.

Diabetes NSW research also revealed a 6.1 per cent incidence of diabetes in Dubbo' "electoral district", 1.1 per cent higher than the national rate of 5 per cent.

More information and a diabetes risk tool can be found at www.diabetesaustralia.com.au.

People living with diabetes can seek support by calling the toll-free Diabetes NSW information line on 1300 136 588.