DVT or Deep Vein Thrombosis is a blot clot which forms in the deep veins of the body, most typically in the large vein which runs through the calf and thigh muscles.
Symptoms can include pain and swelling, and if complications arise a piece of the clot can break off and block one of the blood vessels in the lungs, causing a pulmonary embolism.
Although there is evidence to suggest that anybody can develop DVT and for no apparent reason, risk factors can include age, a family history of blood clots, medical conditions like cancer and heart failure, being overweight and periods of inactivity.
In people who are inactive for long periods of time, such as after an operation, blood collects in the lower parts of the body and legs, which slows down the blood flow and increases the risk of a clot forming. If you are admitted to hospital for an operation which will confine you to a bed for a long period of time, you may be given preventative treatment to prevent blood clots from forming.
If the wall of a blood vessel becomes damaged, the vessel may become blocked which can also result in clotting. Vessel damage can be caused by injuries such as broken bones or muscle damage, while varicose veins and some types of medication such as chemotherapy can also cause them to narrow.
Although symptoms are not always present, some indications of DVT can include the following:
pain and swelling
a reddening of the skin
an aching sensation in the area of the clot
warm skin in the affected area
If your condition becomes serious and you develop a pulmonary embolism (a blod clot in the lungs), you may feel breathless, chest pain or become weak and collapse suddenly.
This type of medication prevents clots in the blood from getting bigger and helps to stop the clot from breaking apart and causing blockages elsewhere in the body, especially in the lungs. Two different types of anticoagulants are used to prevent DVT: heparin, which can be given either as an intravenous injection into your veins, a drip or an injection under your skin, and warfarin, which is taken as a tablet and can be used after initial heparin treatment to prevent further blood clots from occuring.
After having a DVT, compression stockings can help to prevent further clotting and post-thrombotic syndrome (the damage to calf tissue caused by pressure from a clot). As symptoms of post-thrombotic syndrome can take up to a year to materialise following a DVT, compression stockings should be worn every day for at least two years, with a professional review of your prescription every three to six months.
To prevent post-thrombotic syndrome, exercise and keeping the legs raised when seated may also be advised. By keeping your leg raised and your foot higher than your hip, the pressure in the veins of the calf should be lessened and blood should be able to flow easier rather than pooling in the bottom half of your body.
If you have had DVT before or know you are at risk, there are a number of things you can do on long-distance journeys to help reduce your chances of suffering from DVT. These include:
drinking plenty of water
avoiding alcohol which can cause you to become dehydrated
avoiding sleeping pills which can cause immobility
doing simple leg exercises while seated
taking short walks (for example on a plane) where possible
wearing elastic compression socks