Related articles: Orthostatic hypotension
Definition
Orthostatic hypotension consists of a sharp and significant reduction in arterial pressure when a person stands up from a sitting or lying position.
In order to be able to speak for all effects of orthostatic hypotension, this reduction must be at least 20 milligrams of mercury (mmHg) for systolic blood pressure and / or at least 10 mmHg for diastolic blood, with respect to the values detected with the patient in position sitting or lying down (tilting).
Orthostatic hypotension can manifest itself with symptoms of weakness, palpitations, dizziness, confusion or blurred vision, which occur within 3 minutes of taking the upright posture. Some patients also experience falls, syncope and generalized convulsions.
Orthostatic hypotension is the consequence of an inadequate physiological response to the mechanisms that regulate blood pressure following postural changes.
The most frequent causes of orthostatic hypotension include hypovolemia (consequent, for example, to hemorrhage or dehydration), dysfunctions of the neurovegetative system, adrenal insufficiency and the use of certain drugs (vasodilators, antihypertensives, barbiturates and antidepressants tricyclics).
Cardiovascular conditions (such as hypokalaemia and prolonged bed rest), peripheral venous insufficiency and altered cardiac output (constrictive pericarditis, myocardial infarction, tachyarrhythmia or bradyarrhythmias).
Orthostatic hypotension may also depend on endocrine changes, such as hyperaldosteronism, and pheochromocytoma.
The possible neurological causes include, instead, Parkinson's disease, multiple strokes, amyloidosis, spinal cord neoplasms and diabetic, alcoholic or nutritional neuropathy.
Post-prandial orthostatic hypotension is also frequent, especially when associated with excessive alcohol consumption. This condition can be caused by the insulin response to carbohydrate-rich meals and blood sequestration in the gastro-intestinal tract.
There is no lack of idiopathic cases without any pathological significance, especially in women.
Possible Causes * of Orthostatic Hypotension
- Amyloidosis
- Anemia
- Alcoholic ketoacidosis
- Diabetic ketoacidosis
- Diabetes
- Wernicke's encephalopathy
- Pheochromocytoma
- Stroke
- Heart attack
- Heart failure
- Adrenal insufficiency
- Parkinson's disease
- Diabetic neuropathy
- Pericarditis
- Heart failure
- Spinal cord tumors
