When Jaybee Serrano had a sudden pain in his neck four years ago, he went straight to the emergency department at Blacktown Hospital.
Doctors ran a routine test and found the then-34-year-old’s blood-sugar levels were alarmingly high.
"Diabetes is a silent killer," Mr Serrano said.
"Most of my relatives have diabetes and some certainly have passed on due to complications with diabetes."
He lives in a hotspot for the disease.
Of the 219,000 people in Greater Sydney who have both Type 1 and Type 2 diabetes, 65 per cent live in the city’s western suburbs — according to the latest Census data.
Both Type 1 and Type 2 diabetes can be hereditary conditions, but Type 2 can also be influenced by a person's lifestyle.
Doctors warn diabetes is the leading cause of heart attacks, strokes, heart failure, kidney disease and preventable blindness, as well as dementia and some cancers.
The pain in Mr Serrano's neck was fleeting, but the revelation he was pre-diabetic forced him to make tough lifestyle decisions.
Working with his general practitioner, he began cutting out foods like rice and bread and exercised more by playing basketball.
Within three months his blood sugar levels improved — and he's kept up the work to make sure it stays that way.
"I want to be healthy for myself and for my two boys," he said.
Glen Maberly, a senior endocrinologist at Blacktown and Mount Druitt Hospitals, is the director of Western Sydney Diabetes, an organisation trying to coordinate a response to the widespread condition.
He said the actual number of people living with diabetes was likely higher than what the Census estimated.
"You can have diabetes and not know it," he said.
"But all of a sudden, the catastrophic thing will happen, and you'll end up with a heart attack in hospital, and that's not silent.
"Or, you'll end up with an amputation, or you'll end up on dialysis with a kidney replacement."
He said there were three main reasons why diabetes rates were higher in Western Sydney: unhealthy food options, less space to exercise, and greater diversity with ethnicities likely to develop it.
In 2016, Western Sydney Diabetes partnered with Price Waterhouse Cooper to calculate the economic toll diabetes in the region is having, including state and federal government costs, out-of-pocket expenses, loss of productivity and societal costs.
They found the economic hit for an average patient with Type 2 diabetes is $16,124 per year.
All up, this means the high rate of diabetes in Western Sydney costs $1.48 billion a year.
Dr Maberly said the best way people could prevent Type 2 diabetes was by eating healthy foods and exercising.
"However, if we want to turn diabetes around, we have to look at this as a bigger problem."
After 20 years of living with Type 2 diabetes, Russell Ashley still struggles to stick to a strict diet and exercise regime.
If the 69-year-old from Blacktown doesn't stay on top of his blood-sugar levels, activities including walking and driving will leave him exhausted.
He has to go to the bathroom more often and his cuts take longer to heal.
"If I don't take [medication], then I don't have control over my whole body," he said.
"It can be debilitating, very debilitating."
The Western Sydney Leadership Dialogue said better town planning could help the problem, too.
"The sad reality is — for a lot of these families and residents — is they've got better access to a KFC or a McDonalds than they do an actual playground or park," Adam Leto, the director of the not-for-profit think tank, said.
