Postural hypotension, also known as orthostatic hypotension, is low blood pressure when standing up suddenly.  It can cause dizziness, lightheadedness and one may even faint.  It can happen to anyone for a variety of reasons.  It can occur by dehydration, lack of food, prolonged standing in the heat, or being overly fatigued.  It can also be influenced by genetic make-up, aging, medication, dietary and psychological factors, infection and allergies.

Postural hypotension occurs most frequently in people who are taking drugs to control high blood pressure.

Postural hypotension is often mild, lasting only a few seconds or a few minutes after standing up.  However, postural hypotension can be a sign of more-serious problems, so if you frequently have this problem, you need to consult your physician.

Signs and symptoms of postural or orthostatic hypotension include:

• Feeling lightheaded or dizzy after standing up
• Blurry vision
• Weakness
• Fainting (syncope)
• Confusion
• Nausea
• Headache

The elderly are particularly affected, especially those who have high blood pressure or autonomic nervous system dysfunction.  More than 15 percent of people age 65 and older are affected by this condition.

One common occurrence for postural hypotension is after meals.  It causes dizziness and falls after eating.  It is believed to be caused by blood pooling into the vessels of the stomach and intestines.

The use of certain drugs is also commonly associated with leading to postural hypotension.  These medications can be divided into two major categories:

• Drugs used to treat high blood pressure, such as diuretics, beta-blockers, calcium-channel blockers, and angiotensin-converting enzyme (ACE) inhibitors.
• Drugs that have hypotension as a side effect, including nitrates, drugs for Parkinson’s disease, antipsychotics, neuroleptics, anti-anxiety agents, sedative-hypnotics, and antidepressants.

There are common causes of naturally occurring postural hypotension such as dehydration and electrolyte loss.  This may result from diarrhea, vomiting, excessive blood loss during menstruation, or other conditions.

There are certain diseases that can also cause postural hypotension. The diseases or conditions that cause postural hypotension include:

• Central nervous system disorders, such as multiple system atrophy
• Nerve problems, such as peripheral neuropathy or autonomic neuropathy
• Cardiovascular disorders
• Alcoholism
• Nutritional diseases
• vitamin deficiencies
• Spinal cord injuries, and
• Neuropathies associated with cancer, particularly lung cancer or pancreatic cancer