There are thought to be 850,000 people who don not know they have type 2 diabetes.
A record breaking three million people have now been diagnosed with the disease, and experts are warning unless more is done to prevent the condition, the NHS could become burdened with unsustainable costs.
Diabetes sufferer Lynda Marks said dealing with the condition is much easier once you start talking about it.
She said: "It's difficult... to begin with."
More top news
'Water Rats' gang leader killed after Briton murdered
Three alleged neo-Nazis, including two British soldiers, are set to stand trial in March next year, a court has heard.
ITV's Tonight programme tracks down the Romanian criminal mastermind behind one of Britain’s biggest jewellery heist gangs.