Question: Are Cushing's patients prone to developing blood clots, particularly in the lungs? If so, what, if any, precautions should be taken?

Answer: There is some evidence that Cushing's syndrome patients have a greater tendency to form blood clots and that this may be due to increased levels of certain normal clotting factors in their blood. One does not usually form clots in the lungs; rather, the clots form in the deep veins of the legs. Once formed, they can break loose and travel through the major vein in the abdomen, (the inferior vena cava), through the right side of the heart, and out into the pulmonary artery through which the heart delivers blood to the lungs.There, the diameter of the blood vessels rapidly decreases, and the clot becomes lodged in the vessel, preventing blood flow to that part of the lung. This is called a pulmonary embolus.

Unless there is a preexisting history of blood clots (thrombophlebitis, phlebo-thrombosis, or pulmonary embolus), the main precaution is to exercise the legs. Clots tend to form when the blood runs very slowly. Muscle activity squeezes the blood up from the legs, past flap valves in the veins, and back to the heart. Patients should exercise for at least fifteen minutes three or four times a day, especially when they are in a hospital undergoing tests that keep them in bed much of the time. The best exercise is walking, but pushing the balls of the feet against the foot of the bed is also helpful. In addition, leg massage by a physical therapist can achieve a similar result.