More than a million people are affected by type 2 diabetes and dont even know it.
And the risks they face are high: left untreated, the condition can raise the risk of heart attacks, blindness and amputation.
Shocking new figures suggest 24,000 people die every year in England because of poorly managed diabetes.
Yet if doctors catch the condition, it can be controlled with diet and medication.
Type 2 is the most common form of diabetes, accounting for 90 per cent of cases.
Diabetes occurs when the pancreas does not produce enough insulin the hormone that converts glucose into energy or the body stops responding to insulin, triggering high levels of glucose in the blood.
This causes symptoms such as fatigue, thirst, frequent urination, recurrent thrush and wounds that are slow to heal.
Most people associate type 2 diabetes with being overweight, eating junk food or a couch-potato existence.
Yet research suggests that modest weight gain, or even relatively minor disruptions to normal dietary patterns, could be enough to cause it.
So how do you know if you are at risk? Here, we reveal the less well-known factors that can increase your chances of developing this serious condition.
HAVING AN APPLE SHAPED BODY
You dont have to be obese to be at risk. Just carrying a few extra pounds around the waistline can be enough to cause the condition. Diabetes UK says a woman is at risk if her waist reaches 31.5in (80cm).
For a white or black man its 37in (94cm), and 35in (90cm) for South Asian men.
This means people who may appear relatively slim but have a pot belly or apple shape could be more at risk than someone who looks larger but deposits fat around their upper body, buttocks or thighs.
This is because visceral fat, the type of fat that lies around the organs in the abdomen, is thought to pump out molecules that disrupt the normal balance of glucose and insulin, and also leads to damaging inflammation in blood vessels.
BURNING THE MIDNIGHT OIL
if you regularly get less than five hours sleep, your risk of getting diabetes is double that of someone who gets seven to eight hours.
Scientists at Boston University in the U.S. studied 1,500 volunteers aged over 50, recording their sleep patterns and testing their levels of glucose.
Five hours or less a night more than doubled the risks, while six hours was linked with a 60 per cent rise in risk.
Its thought the danger arises because lack of rest upsets the bodys circadian rhythm, the internal clock that regulates natural sleep and wake cycles.
Being awake when we should be asleep increases the release of the stress hormone cortisol, which promotes the generation of glucose (to provide energy to the body to keep it going), says Julian Halcox, professor of cardiology at Cardiff University.