We wouldn’t normally expect our blood to clot unless we’d cut ourselves; and then we need a clot to form to stop the bleeding. Sometimes the normal clotting function of our body can go wrong and blood becomes a solid mass within a blood vessel that has not been cut – causing what is known as a thrombosis.

A deep vein thrombosis (or DVT) is when a blood clot forms in the veins deep within the leg, usually in the calf or thigh. The blood clot then blocks the flow of blood partially or completely and causes symptoms such as swelling and reddening of the leg, pain (which may only be noticeable, or get worse, when standing or walking), increased warmth in the lower leg, and discoloured skin.

Once a clot is in the thigh there’s about a 10% chance of it breaking off and travelling up into the right side of the heart and then through in to the lung artery, where it will block the blood flow to the lungs. This is called a pulmonary embolism (PE) and a large clot can block the entire blood supply, starving the lungs of oxygen – and can be fatal. Symptoms of PE may include breathlessness, chest pain and coughing up blood.

Office Workers have double the risk

Every year, an estimated 25,000 people in England die as a result of deep venous thrombosis and blood clots in the under 40’s have claimed over 1000 deaths in the last four years. While the greatest risk factor for DVT is surgery, many people associate it with long-haul flights and the contraceptive pill. Smoking, obesity and a generally sedentary lifestyle also all increase the likelihood of problems. However, office workers have double the risk of DVT – and women who sit for a long time every day have up to triple the risk of a dangerous blood clot.

Professor Richard Beasley, of New Zealand, as termed the association between sitting at a PC for long periods and the development of DVT and then pulmonary embolism as “e-thrombosis”. His research has shown that being seated at the computer for 10 hours in a 24 hour period and including 2 hours without getting up, is related to highly increased risk. For every extra hour at your desk, the risk of clots increases by 10%, and the risk doubles if you eat lunch at your desk rather than getting up and eating elsewhere. Once you have sat at your desk for 90 minutes, the blood flow behind your knees decreases by 50 per cent, significantly increasing the chance of a DVT.

Take a break, get up and move

It is vital to take regular breaks every hour or so: get up, walk about, rotate your ankles and stretch out your calf muscles. It’s also important to have regular drinks to stay hydrated as dehydration is another risk factor for DVT.

If you have any of the above DVT symptoms you should visit your GP as soon as possible as, once diagnosed, the clots are easily treatable with anti-coagulant drugs such as warfarin and the use of compression stockings.  However, if you’re fairly young it can very easily be confused with less serious conditions or mistaken for a sore or aching muscle.

For more information about thrombosis visit Lifeblood  – www.thrombosis-charity.org.uk

And don’t sit chained to your desk for hours on end. It’s just not worth the risk.