Orthostatic hypotension is a condition of abnormal blood pressure regulation upon standing. The blood pressure quickly decreases, more than 20/10 mm Hg, when rising from a lying down or sitting position to a standing position.
As you stand, blood falls toward your lower body in response to gravity. To help keep blood in the upper body:
- Blood vessels in the lower body will tighten to help push blood back up.
- The muscles in the lower body contract, or squeeze, to help push blood to upper body.
- The heart will contract a little harder to pump blood up toward the brain.
Blood pressure is also affected by the amount of blood in the blood vessels. Low levels of blood will decrease the blood pressure and make it harder for the body to compensate when you stand. Low blood volume, called hypovolemia, is the most common cause of orthostatic hypotension. It may be due to:
- Excessive use of loop diuretic medications
- Vasodilator medications, such as nitrate preparations, calcium channel blockers, or angiotensin-converting enzyme (ACE) inhibitors
- Prolonged bedrest
- Addisons disease with inadequate salt intake
Orthostatic hypotension will occur when 1 or more of these factors do not work as expected. It may be associated with:
- Diseases or conditions that impair the nervous system or nerves that control the widening or shrinking of blood vessels
- Decreased ability of the heart to contract or reaction of blood vessels
- Medications that can affect the nervous system or cardiovascular system
- Alcohol—can slow the reaction of the nervous system
Factors that increase your chance of orthostatic hypotension include:
- Increased age
Use of certain drugs such as:
- Loop diuretics
- monoamine oxidase (MAO) inhibitors
- Tricyclic antidepressants
- Tetracyclic antidepressants
- Phenothiazine antipsychotic drugs
- Inadequate fluid intake
- Prolonged bedrest
- Certain diseases or conditions:
Orthostatic hypotension may cause:
Mild-to-moderate reduction in brain blood flow:
- Visual blurring
Severe reduction in brain blood flow:
- Fainting (syncope) or brief loss of consciousness
Exercise or having eaten a heavy meal may worsen symptoms.
Orthostatic hypotension is diagnosed when symptoms are present and there is a measured reduction in blood pressure while standing, which is relieved by lying down.
When possible, treatment will focus on resolving the orthostatic hypotension completely. If a complete resolution is not possible, treatment will focus on managing symptoms.
Treatment will depend on the cause. Examples include:
- Adjusting or stopping medications that cause problems.
- Avoiding prolonged bed rest. Make sure to sit up each day. Start slowly and increase the time and frequency.
- Preventing dehydration by increasing fluid and electrolyte intake.
Common approaches include:
The doctor may recommend prescription medications to increase blood pressure.
Dietary changes may also help increase blood pressure or prevent very low blood pressure. A dietitian may help create a diet plan. Steps may include:
- Increasing salt intake.
- Eating smaller, more frequent meals with fewer carbohydrates that may help to avoid low blood pressure after eating.
- Limiting or eliminating alcohol.
Behavioral changes that may help include:
- Using fitted elastic stockings that go up to the waist.
- Learning to slowly move from a lying or sitting position to a sitting or standing position.
- Avoiding sitting or standing still for prolonged periods of time.
There is no way to prevent orthostatic hypotension if it is a result of other diseases or conditions. However, if your orthostatic hypotension relates to medications, dehydration, or bedrest, you should talk with your healthcare provider about treatment options.
- Reviewer: Michael J. Fucci, DO
- Review Date: 08/2014 -
- Update Date: 03/24/2015 -