An estimated 900,000 Americans experience a deep vein thrombosis (DVT) each year and as many as 100,000 of these blood clots are fatal. There are numerous causes of blood clots in the deep veins of your legs, but when you hear about DVT, you often think about passengers getting a blood clot during extended air travel. Although long-distance flights are associated with DVTs, car, bus or train journeys longer than four hours also place you at increased risk of a blood clot. Thankfully, most travelers never develop a DVT, but it pays to know which factors increase your likelihood of developing a blood clot during a long journey. Once you are aware that you are at increased risk, you can take precautions to minimize a DVT and remain vigilant for symptoms of a blood clot in your leg.
DVT risk factors
There are some risk factors for DVT that you cannot change. For instance, you are at greater risk of developing a blood clot once you hit your forties. If you had a previous blood clot or you have close relatives who suffered blood clots, you are more prone to DVT, as up to 8% of the population have a genetic predisposition to increased blood clotting known as thrombophilia. Other health-related risk factors for DVT are an injury or operation during the last three months, limited mobility, varicose veins, Crohn’s disease or ulcerative colitis, cancer, heart disease or stroke. If you are pregnant or delivered a baby within the last six weeks, your blood is also more likely to clot.
There are a few modifiable factors that increase your risk of a DVT. Firstly, smoking is a major risk factor for blood clots, so quitting your habit will help lower your risk of DVT. A body mass index over 30kg/m2 also makes you more prone to blood clots, so weight loss to achieve a healthy body weight can lower your DVT risk. Thirdly, your choice of contraceptive has a bearing on your risk of a blood clot, with estrogen-containing birth control, such as the combined pill, patch and vaginal ring, making you more susceptible to DVT. If you still wish to use hormonal birth control, progesterone-only contraceptives, such as the mini pill, injection, implant and IUD, are a safer option. As hormone replacement therapy (HRT) contains estrogen, taking HRT is another risk factor for blood clotting, so you may wish to explore alternative options to relieve menopausal symptoms.
Reducing your risk of DVT
If you are aware you are at greater risk of a DVT, you should seek advice from your doctor before you travel. Depending on the extent of your risk, they may advise against long-distance travel and recommend you holiday closer to home. Alternatively, your doctor may prescribe medication to make your journey safer. However, for many travelers at increased risk of blood clots, compression stockings alone are sufficient to lower the risk of DVT. Flight socks make blood clots less likely in your deep leg veins by applying pressure to your ankles, which promotes greater blood flow. Compression stockings for flights are widely available to buy, but it is essential you buy the correct size or you will not receive protection against DVT.
Besides flight socks, wearing loose clothing is recommended during your journey. You should also prevent dehydration by drinking plenty of fluids free from caffeine and alcohol before and during your flight. Additionally, you should stay as active as possible, even if this just means you exercise your feet and legs while seated. To avoid immobility, you should also refrain from taking sleeping pills during your journey.
Although sometimes it is possible to get a blood clot without symptoms, during and after long-distance travel you need to stay vigilant for symptoms of DVT to allow you to seek medical help as soon as possible. Signs that you may have a blood clot in your leg veins include a swollen leg, redness and warmth in your affected leg and calf pain that may feel similar to cramping. If the blood clot breaks away from your leg vein and travels to your lungs, symptoms of a life-threatening pulmonary embolism may appear. Therefore, look out for sudden shortness of breath, chest pain, fast pulse, dizziness and bringing up blood when you cough.
Although your journey will hopefully go by without any problems, it pays to know whether you are more likely to experience DVT so that you can prepare for travel and recognize any adverse symptoms.