sudden, temporary spastic contractions of blood vessels.
General and local (regional) vascular crises are distinguished. The former cause a general increase in arterial pressure and occur in hypertension, pheochromocytoma, and so forth. Regional crises disrupt the blood supply of individual organs. Local crises may involve the blood vessels of the brain, causing headaches, dizziness, and unconsciousness; the coronary arteries (in angina pectoris, myocardial infarction); and blood vessels of the legs (in intermittent claudication) or intestine (in colic). Vascular crises may result from nervous strain, hormonal disturbances (for example, in women during the climacteric), abrupt changes in meteorological conditions (such as atmospheric pressure), and certain brain diseases. All vascular lesions predispose to vascular crises. Treatment involves elimination of the causes as well as symptomatic therapy.