Orthostatic hypotension, also called postural hypotension, is a sudden fall in blood pressure that occurs when you stand up quickly.
When you stand up, gravity pulls blood into your legs and your blood pressure begins to fall. Certain reflexes in your body compensate for this change. Your heart beats faster to pump more blood and your blood vessels constrict to prevent blood from pooling in your legs.
Many drugs can affect these normal reflexes and lead to orthostatic hypotension. These reflexes may also begin to weaken as you age. For this reason, orthostatic hypotension is more common in older adults.
According to a 2011 study, about 20 percent of people older than 65 experience orthostatic hypotension.
People with orthostatic hypotension may feel dizzy when they stand up. The condition is often mild and lasts for just a few minutes after standing. Some people may faint or lose consciousness.
There are many causes for orthostatic hypotension. These include:
- anemia, or low red blood cell count
- a drop in blood volume, called hypovolemia, caused by certain drugs such as thiazide diuretics and loop diuretics
- heart conditions, such as a heart attack or valve disease
- diabetes, thyroid conditions, and other diseases of the endocrine system
- Parkinson’s disease
- long-term bed rest or immobility
- hot weather
- blood pressure medications and antidepressants
- alcohol or drug use while taking blood pressure medications
The most common symptoms of orthostatic hypotension are dizziness and lightheadedness upon standing up. The symptoms will usually go away when sitting or lying down.
Other common symptoms include:
Less common symptoms include:
If your doctor suspects that you have orthostatic hypotension, they’ll check your blood pressure while you’re sitting, lying down, and standing.
Your doctor can diagnose orthostatic hypotension if your systolic blood pressure drops by 20 millimeters of mercury (mm Hg), or your diastolic blood pressure drops by 10 mm Hg within 3 minutes of standing up.
To find the underlying cause, your doctor may also:
- conduct a physical exam
- check your heart rate
- order certain tests
The tests your doctor may order include:
- complete blood count (CBC) to check for anemia
- electrocardiogram (EKG) to check the rhythm of your heart
- echocardiogram to check how your heart and heart valves are functioning
- exercise stress test, which measures your heart rate during exercise
- tilt-table test, in which you lie on a table that moves from horizontal to upright to test for fainting
Treatment for orthostatic hypotension depends on the cause. Recommended treatments may include the following lifestyle changes:
- Increase your fluid and water intake and limit your alcohol intake if you’re dehydrated.
- Stand up slowly when getting out of a chair or bed.
- Perform isometric exercises before getting up to help raise your blood pressure. For example, squeeze a rubber ball or a towel with your hand.
- Work with a doctor to adjust your dose or switch to another medication if medication is the cause.
- Wear compression stockings to help with circulation in your legs.
- Avoid crossing your legs or standing for long periods of time.
- Avoid walking in hot weather.
- Sleep with the head of your bed slightly elevated.
- Avoid eating large carbohydrate-rich meals.
- Add additional salt to your daily meals to retain fluid.
For severe cases, your doctor may prescribe drugs that work to increase blood volume or constrict blood vessels. These drugs might include:
- fludrocortisone (Florinef)
- midodrine (ProAmatine)
- erythropoietin (Epogen, Procrit)
In most cases, treating the underlying condition will cure orthostatic hypotension. With treatment, people who experience orthostatic hypotension can reduce or eliminate symptoms.