Compression stockings are a specialized hosiery, designed to help prevent the occurrence of, and guard against further progression of venous disorders such as edema, phlebitis and thrombosis. Compression stockings are elastic garments worn around the leg, compressing the limb. This reduces the diameter of distended veins and causes an increase in venous blood flow velocity and valve effectiveness. Compression therapy helps decrease venous pressure, prevents venous stasis and impairments of venous walls, and relieves heavy and aching legs. Knee High Compression Hose are used not only to help increase circulation, but to also help prevent the formation of blood clots in the lower legs, as well as aiding in the treatment of ulcers of the lower legs. “The majority of venous ulcers heal with compression bandages, however ulcers frequently recur. Clinical guidelines therefore recommend that people continue to wear compression, usually in the form of hosiery (tights, stockings, socks) after their ulcer heals, to prevent recurrence.”  “Optimal gradient pressure is 18mmHg at the ankle, 14mmHg at the calf, and 10mmHg at the knee.”  Although, according to an article published by JAMA, it was concluded that “non-custom-made graded elastic stockings with 24 mm Hg of pressure at the ankle are effective in decreasing volume, circumference, and symptoms in the lower leg in patients with minimal problems during a one-week period.”  “Graded elastic compression stockings on the lower leg were evaluated for their ability to (1) decrease leg volume, (2) decrease circumference, and (3) alleviate discomfort.”  The measurement used for compression stockings, is mmHg, otherwise known as millimeters of mercury. Millimeter of mercury (mmHg) is a non-SI unit of pressure. It is the atmospheric pressure that supports a column of mercury 1 millimeter high. The unit is named after Evangelista Torricelli, Italian physicist and mathematician, for his discovery of the principle of the barometer in 1643.  Unlike traditional dress or athletic stockings and socks, compression stockings use stronger elastics to create significant pressure on the legs, ankles and feet. Compression stockings are tightest at the ankles and gradually become less constrictive towards the knees and thighs. By compressing the surface veins, arteries and muscles, the circulating blood is forced through narrower circulatory channels. As a result, the arterial pressure is increased, which causes more blood to return to the heart and less blood to pool in the feet. There are two types of compression stockings, gradient and anti-embolism.