A psychophysiologic disorder of the circulatory system involving blanching, swelling and /or cyanosis (blue appearance due to a lack of oxygen) of the fingers and,less often, the toes. The condition is due to spasmodic constriction of blood vessels, which interrupts the flow of blood to the extremities.The disease was first described by the French physician Maurice Raynaud, in 1862. It occurs primarily in tense, underweight women and only rarely in men. The attacks are most commonly precipitated by cold, but emotional stress is believed to play a decisive role in many instances—and for this reason the condition is included among the psychophysiologic disorders. Experiments have shown that if patients are placed in a room at moderately low temperature, discussion of a stressful life situation will induce a drop in finger temperature and a characteristic Raynaud attack (Mittelmann and Wolff, 1939).Attacks may sometimes be prevented if the patient wears extra clothing in cold weather (or moves to a warmer climate), avoids emotional stress and exhaustion, and eliminates the use of tobacco, since it interferes with circulation in the extremities. Many patients respond well to psychotherapy or hypnotherapy, but in severe cases it may also be necessary to sever the nerves that control the contraction of the blood vessels in the affected parts (sympathectomy) to avoid the danger of gangrene.