In some people, especially older adults, blood pressure drops too much when they sit or stand up (a condition called orthostatic hypotension or postural hypotension). Symptoms of fainting, lightheadedness, dizziness, confusion, or blurred vision occur within seconds to minutes after standing (especially after lying in bed or sitting for a long time) and quickly go away when the person lies down. However, some people fall, faint, or, very rarely, have a brief seizure. Symptoms are more common and worse after people exercise, drink alcohol, and/or eat a large meal, or have a lack of fluids (dehydration).
Dizziness or lightheadedness when standing occurs in about 15 to 20 percent of older adults. It is more common in people with comorbidities, especially high blood pressure, and in people who live in long-term care facilities. Many falls can be caused by dizziness when standing. Older adults should avoid standing for long periods of time.
The increased incidence in older adults is due to a decrease in the responsiveness of the receptors that regulate blood pressure combined with increased stiffness of the artery walls, which makes it more difficult for the arteries to move more blood to increase blood pressure. Decreased receptor responsiveness slows the normal response of the heart and blood vessels to standing. Paradoxically, high blood pressure, which is more common in older adults, may contribute to decreased receptor sensitivity, increasing the risk of dizziness when standing.
What causes it?
A number of disorders can cause problems with blood pressure regulation and lead to dizziness when standing. Types of causes include:
- Autonomic nervous system dysfunction due to disorders or medications
- Reduced pumping ability of the heart
- Hypovolemia (decreased blood volume)
- Faulty hormone response
- Causes vary depending on whether the symptoms are new or have been present for some time.
The most common causes of new dizziness when standing up include:
- Decreased blood volume (possibly due to dehydration or blood loss)
- Medications
- Prolonged bed rest
- Underactive adrenal glands (adrenal insufficiency)
In addition, the most common causes of dizziness when standing up that have been present for a long time (chronic) include: Age-related changes in blood pressure regulation, medications.
Treatment
Any cause is treated when possible, including changing or stopping any medications that are causing it. However, many causes cannot be cured and people must take steps to reduce their symptoms. These include lifestyle changes and medications.
People who need to be on bed rest for long periods should sit up every day and exercise in bed when possible. People who are lying down or sitting should stand up slowly and carefully. In general, drinking enough water, limiting or avoiding alcohol, and exercising regularly when possible are helpful.
Regular moderate exercise increases the muscle tone in the blood vessel walls, which helps reduce the pooling of blood in the legs. Sleeping with the head of the bed raised may help relieve symptoms. For some people, increasing salt intake can increase fluid retention and relieve symptoms. Your doctor may recommend that you increase your salt intake by adding more salt to your food or taking sodium chloride tablets. However, increasing your salt intake may not be recommended for people with heart disease.
