Long hours in a car, the lower limbs can appear swollen, medically known as “traveler’s edema”. Therefore, when riding in a car, do not always sit, should always change the position, or stand for a while or elevate the lower limbs to sit for a while, also can be used to massage the lower limbs from top to bottom to help blood flow back. Causes of traveler’s edema: 1, due to long-distance travel by train or on foot, due to gravity, the lower limbs and sagging upper limb venous reflux is restricted, increasing the hydrostatic pressure in the capillaries, resulting in fluid seepage in the subcutaneous tissue gap. 2, due to increased secretion of aldosterone during uprightness, resulting in increased renal tubular reabsorption of water and sodium related. It is more common in women and may be related to endocrine disorders; it is more common in obese people because they need to rely on peripheral vasodilatation to distribute body heat, prompting an increase in venous pressure in the lower limbs and an increase in capillary filtration pressure. Travelers edema as long as you stop traveling, 2-3 days to recover, no need to treat with drugs. Sometimes salt intake can be appropriately restricted, and water does not necessarily need to be strictly controlled. When edema is significant, a small amount of dihydrocotrimoxazole can be used, 25mg (1 tablet) twice a day for 2 days, and the edema will subside. Clinical diagnosis of edema in travelers: Edema is often one of the important manifestations of certain diseases, and can be caused by more than 30 kinds of causes, the most common being heart, liver and kidney diseases. However, there are some patients with edema who have no abnormal findings by multiple examinations and laboratory tests, and after long-term observation, the health of these people is not significantly affected. In view of the fact that the causes and nature of this type of edema are not well understood, it is medically called benign edema also known as functional edema. Traveler’s edema is mostly seen in people over 40 years of age and fat people, and is more common in women, and it is a kind of benign edema. It manifests as numbness, swelling and heaviness in the hands and feet, and the edema is more common in the two lower limbs and is more flaccid, and the hands are often involved; it is mostly mild edema and has little relationship with water intake; the edema can disappear completely after rest and position change, often disappearing in the morning and appearing in the afternoon.