Men in England are to be offered screening for a potentially fatal blood vessel condition.
AAA can be fatal, but can be repaired if detected early
Abdominal aortic aneurysm (AAA), which can cause one of the body's main blood vessels to burst, is the third most common cause of death among older men.
Over the next five years, ultrasound scan screening will be rolled out across 60 centres to cover all men aged 65 and over.
The Department of Health says this will save 700 lives a year within 10 years.
Doctors welcomed the announcement, but called for more details to be given on how the screening programme will be funded and organised.
The announcement comes ahead of a speech on the NHS by Prime Minister Gordon Brown on Monday, in which he is expected to stress the importance of measures to prevent ill health.
So far about £3m has has been set aside for pilot projects this year which will offer screening to 32,000 men in England. Eventually it is hoped 270,000 men a year will be screened.
Men are six times more likely to have an aneurysm than women. If detected early enough, the condition can be corrected by surgery.
The abdominal aorta carries blood to the intestines and other organs nearby and if an aneurysm occurs in this area it can be fatal, with most patients dying before they get to emergency care.
Announcing the screening programme, Health Secretary Alan Johnson said: "We should be looking at how to stop disease taking hold in the first place.
"The programme is a very good example of the kind of measures we will have to make more widely available if we are going to expect clinicians and public to take more responsibility for early identification and lifestyle changes."
This is the NHS's first men-only screening programme. AAA kills over 3,000 men a year - roughly twice as many deaths as cervical cancer for women, which has its own screening programme.
Jonothan Earnshaw, honorary secretary of the Vascular Society, which represents specialists in this area, said: "We welcome the announcement of an abdominal aortic aneurysm screening programme and look forward to working with the government.
"Key to success will be funding to train technicians to undertake the scans and for the organisational infrastructure of the scheme. We await further information on this."
Conservative health spokesman Andrew Lansley said his party had been arguing for years for a national screening programme for abdominal aortic aneurysms.
He said: "This has taken so long because it is something which particularly affects men over the age of 65 so is not regarded as a priority."