Venous thromboembolism (VTE) includes deep vein thrombosis (DVT) and pulmonary embolism (PE), and affects two people per 1,000 each year. In DVT, a blood clot develops in a deep vein (usually in the leg, but sometimes in the brain, arm or trunk). PE means part of the clot detaches and travels to the lungs, blocking blood flow, sometimes fatally.
The causes
Over half of those who develop DVT have identifiable risk factors. These include a personal or family history of VTE, being older, pregnant or immobilised (travel, illness, injury or an operation, especially one involving the lower body), taking hormones (oral contraceptive pill or HRT), and dehydration.
People are also more at risk if they smoke, are obese, have varicose veins, heart failure or cancer, or blood that clots more…