I had a DVT and a minor pulmonary embolism last year, apparently induced by not standing up or walking around on the plane. Everything was fine with the anticoagulants and I am now off them. Is it safe for me to fly now? If so, what precautions would you recommend? A: Yes, if you take some precautions, you can fly again. Before I express them, I would also like to address a topic that is important to your health. The occurrence of deep vein thrombosis and pulmonary embolism shows that your blood has a tendency to clot under some stressful conditions, such as flying for hours at a time. Having had a DVT or pulmonary embolism before means that they are likely to happen again, even if you don’t fly. Without anticoagulants that inhibit clot formation, the incidence of DVT and pulmonary embolism over the next ten years will be 30 to 50 percent. Many doctors, including mine, will recommend that you use an anticoagulant, such as warfarin. Prolonged sitting and dehydration can create an environment in the veins that encourages clots to form. Being in bed all the time, with one leg bent and other limbs inactive, also predisposes you to DVT and pulmonary embolism. Here are four tips for you or others who fly for long periods of time to reduce the chances of DVT and pulmonary embolism. 1. Maintain adequate water intake. Bring a few extra bottles of water and drink enough water will get you up and moving to the bathroom many times. This is related to the third recommendation. 2.Avoid alcohol. Alcohol can make you dehydrated. It can also make you drowsy, so you will be less active. 3. Move your muscles. Stand up, stretch your arms and legs, at least once an hour. Walk up and down the aisles, or walk slowly in place. Standing or sitting, do some simple exercises, such as straightening the calves, stretching the legs, toes up and down. Put a minimum of things in front of your seat to make enough space for you to move around. 4. Try compression stockings. Compression stockings will continue to gently squeeze the blood from the legs back into the heart. This will prevent ankle edema during long air flights.