Etiology and risk factors for developing orthostatic hypotension.

Orthostatic hypotension (OH) is regarded as a decrease primarily in systolic blood pressure on changing position from supine to erect. Based on clinical criteria, it is characterized by a decrease in systolic pressure of 20 mmHg and diastolic pressure of 10 mmHg within 1 to 3 minutes of standing after being supine. It is most prevalent in, although not limited to, the elderly population and is characterized by a variety of problems, including diminished cognition and disturbed emotion along with gate problems, falls, and brain and cardiovascular difficulties. Although often seen as an age-related condition, occurrence of OH is also associated with a number of autonomic nervous system neurodegenerative disorders. Medications may play a direct role in the risk of triggering OH; these drugs include, but are not limited to, agents used in the treatment of hypertension, myocardial ischemia, psychosis and schizophrenia, depression, Alzheimer and Parkinson disease as well as a vaccine approved for the prevention of cervical cancer. Most of these agents increase the risk for triggering OH through varying vasodilative mechanisms or through sympathetic nervous system interruption; for other drugs, no mechanism of action has been identified. These factors should be considered when diagnosing OH and when prescribing remedies for both patients with OH and those without OH; medication's contributions to the severity and/or risk of developing OH could limit their use. However, their effects could be attenuated or even eliminated by modifying drug dosages.