A thrombosis is the formation of a blood clot or “thrombus” that wholly or partially blocks the blood vessel in which it forms. When it occurs in one of the body’s deeper veins, it is known as a deep-vein thrombosis or DVT. DVTs often occur in the veins of the leg.
A deep-vein thrombosis is not life-threatening in itself. But if part of the blood clot breaks off and moves through the body’s circulatory system and into the lungs, it can get stuck there and result in the far more serious condition known as a pulmonary embolism.
Anyone can experience a DVT. But some persons run a higher risk of doing so. Recent studies have also revealed a greater risk of incurring a DVT among people making journeys of more than four hours, be this by car, bus, train or air. This is because journeys of such length involve hours of sitting with the legs bent, a position which restricts and slows down the flow of blood through the veins. Slower-flowing blood has a greater tendency to clot, and it is this that raises the chances of a DVT developing.
If you are at a higher risk of developing a deep-vein thrombosis (e.g. if you have already suffered a thrombosis, have a chronic heart or lung condition, are substantially overweight, are pregnant or have recently undergone an operation), we advise you to contact your doctor before your departure to discuss taking a blood-thinning agent and/or wearing compression stockings for the flight.
You are at greater risk of developing a deep-vein thrombosis if:
- you are over 60 (the risk increases with age)
- you suffer from a cardiac insufficiency or chronic venous insufficiency (CVI)
- you have already suffered a DVT or a pulmonary embolism
- a close relative has suffered a DVT or a pulmonary embolism
- you are taking oral contraception containing oestrogen (the Pill) or are undergoing hormone replacement therapy
- you are pregnant
- you smoke
- you recently had an operation or suffered an accident, especially involving the abdomen, the pelvis or the legs
- you have cancer
- you have a hereditary blood-clotting condition (thrombophilia) or any of certain other blood disorders
- your leg is currently in plaster or must otherwise be kept still
What you can do to help minimise the risk of developing a DVT:
- Drink enough while on board
- Don’t smoke before flying
- Don’t drink alcohol or coffee before or during the flight
- Don’t take any sleeping tablets or sedatives
- Don’t cross your legs while seated
- When circumstances permit during the flight, get up, find a little space near your seat and stretch your arms and legs
- Bend and stretch your legs from time to time while seated, and make small circular movements with your legs and feet
- Wear loose and comfortable clothing for the flight