Too many adults in Kingston are untested for diabetes, charity Diabetes UK has claimed.
Nearly 3,000 people in Kingston may be unaware they have debilitating type 2 diabetes, which can cause blindness, amputation and heart disease.
These people make up 35 per cent of the total number of people in the borough thought to have type 2 diabetes, which is the fourth highest rate of undiagnosed cases of London's 32 health authorities.
Roz Rosenblatt, Diabetes UK London manager, said the figures were "truly alarming" and that more people needed to get tested.
She said: "PCTs need to better prioritise screening of at-risk groups and improve uptake of programmes such as NHS health checks.
"We face a bleak future of spiralling NHS costs and worsening public health if diagnosis rates for type 2 diabetes do not improve."
The new estimates come from Diabetes Health Intelligence, a strategic programme of Yorkshire and Humber Public Health Observatory.
Diabetes UK is asking residents to take an online test to determine their risk of diabetes at diabetes.org.uk.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here