FEWER than half of people eligible for a NHS health check in England have taken up the offer, despite it being free to everyone over 40.
The routine check can pick up heart problems early and help to prevent dementia, plus highlight the need to stop smoking, NHS England said.
The check-up takes 20 minutes and is carried out by a GP or nurse.
It involves tests on blood pressure, weight and height, and is offered every five years up to the age of 74.
Around 7.15 million people have had a free health check since 2013, yet 15 million are eligible, NHS stats show.
NHS England said identifying people with an irregular heartbeat or high blood pressure and giving them treatment would help to prevent dangerous blood clots which could lead to strokes.
And if more people went for their health check, the number of people having a stroke or other heart problems would reduce, potentially preventing thousands of cases of vascular dementia.