- 1. Subnormal arterial blood pressure. SYN: hypopiesis. 2. Reduced pressure or tension of any kind. [hypo- + L. tensio, a stretching]- arterial h. h. (1).- idiopathic orthostatic h. the tendency for blood pressure to drop for unknown reasons on assuming upright posture.- induced h., controlled h. deliberate acute reduction of arterial blood pressure to reduce operative blood loss by pharmacologic means during anesthesia and surgery.- intracranial h. subnormal pressure of cerebrospinal fluid; most commonly following lumbar puncture and associated with headache, nausea, vomiting, stiffness of the neck, and sometimes fever; may also result from dehydration.- orthostatic h. a form of low blood pressure that occurs in a standing posture. SYN: orthostatic hypopiesis, postural h..
* * *hy·po·ten·sion 'hī-pō-.ten-chən n1) abnormally low pressure of the blood called also low blood pressure2) abnormally low pressure of the intraocular fluid
* * *n.a condition in which the arterial blood pressure is abnormally low. It occurs after excessive fluid loss (e.g. through diarrhoea, burns, or vomiting) or following severe blood loss (haemorrhage) from any cause. Other causes include myocardial infarction, pulmonary embolism, severe infections, allergic reactions, arrhythmias, acute abdominal conditions (e.g. pancreatitis), Addison's disease, and drugs (e.g. an overdose of the drugs used to treat hypertension).Some people experience a temporary fall in blood pressure when rising from a horizontal position (orthostatic hypotension). Temporary hypotension may result in a simple faint (syncope). The patient becomes light-headed, sweats, and may develop impaired consciousness. In severe cases peripheral circulatory failure (cardiogenic shock) develops, with unrecordable blood pressure, weak pulses, and suppression of urine production. The patient is placed flat, with legs elevated, and given oxygen. Fluid and blood are replaced by an intravenous infusion as required. Specific treatment of the cause is provided (e.g. corticosteroids in Addison's disease).
* * *hy·po·ten·sion (hi″po-tenґshən) 1. abnormally low blood pressure; seen in shock but not necessarily indicative of it. 2. abnormally low tension or pressure within any fluid-containing bodily structure.
Medical dictionary. 2011.