US:US vice-president Dick Cheney has been treated for a blood clot in his left leg after he complained of mild discomfort in his calf following a nine-day trip involving 65 hours of air travel.
Mr Cheney (66) returned to work immediately after the diagnosis at a Washington hospital but he will take anti-coagulant drugs for several months. The vice-president, who has had four heart attacks and undergone quadruple bypass surgery, was treated in 2005 for aneurysms behind both knees and has had stent-grafts implanted in both legs.
Although his doctors gave few details of this week's treatment, other medical experts say it is unlikely that the blood clot is connected to his earlier surgery.
If Mr Cheney were to resign on health grounds, a new vice-president chosen by President George Bush would have to be approved by both houses of Congress.
