Orthostatic Hypotension

Definition

Orthostatic hypotension refers to a reduction of blood pressure (systolic blood pressure that occurs when the heart contracts) of at lest 20 mmHg or a diastolic pressure (pressure when the heart muscle relaxes) of at least 10 mmHg within three minutes of standing.

Symptoms

Orthostatic hypotension can be caused by several different disorders that affect the entire body (systemic disorders), the central nervous system (CNS, consisting of the brain and spinal cord), and the autonomic nervous system (peripheral autonomic neuropathy) or as a result of taking certain medications that are commonly prescribed by clinicians. Systemic causes can include dehydration, prolonged immobility or an endocrine disorder called adrenal insufficiency. Diseases of the CNS that can cause orthostatic hypotension include MSA (multiple systems atrophy), Parkinson's disease, multiple strokes, brain stem lesions, myelopathy.

Medications that can cause orthostatic hypotension include Tricyclic antidepressants, antipsychotics, monoamine oxidase inhibitors, antihypertensives, diuretics, vasodilators, Levodopa, beta-blockers (heart medications), and blood pressure medications that inhibit a chemical called angiotensin (angiotensin-converting-enzyme inhibitors). Disorders that cause peripheral autonomic neuropathy include diabetes mellitus, amyloidosis, tabes dorsalis (late manifestations of syphilis infection), alcoholism, nutritional deficiency, pure autonomic failure or paraneoplastic syndromes.

The most common symptoms of orthostatic hypotension include weakness, lightheadedness, cognitive impairment, blurred vision, vertigo and tremulousness. Other symptoms that have been reported include headache, paracervical pain, lower back pain, syncope, palpitations, angina pectoris, unsteadiness, falling, and calf claudication.