In an interview, Dr. Gibbons said orthostatic hypotension can be “a presymptomatic sign of Parkinson’s disease, dementia and other disorders of the autonomic nervous system” for which drug treatments are now being studied in hopes of slowing down their progression.
Orthostatic hypotension can also have a less ominous occasional cause like becoming dehydrated or overheated. Or it may be precipitated by a drop in blood sugar or eating a big meal, especially one accompanied by alcohol. But if a heart condition, neurological or endocrine disorder is the underlying cause, orthostatic hypotension is likely to occur more frequently.
Certain medications, including those used to treat high blood pressure, depression, psychosis, erectile dysfunction, Parkinson’s disease, urinary frequency in men and muscle spasms, can increase the risk of a precipitous drop in blood pressure when standing up. For example, Dr. Gibbons said, diuretics used to treat high blood pressure can be “problematic” and might be replaced by medications less likely to cause a drop in blood volume that limits the body’s ability to adjust to standing.
Dr. Lewis A. Lipsitz, geriatrician and director of the Marcus Institute for Aging Research in Boston, said people with especially high blood pressure are more susceptible to orthostatic hypotension because hypertension impairs the heart’s ability to pump blood, thickens blood vessels that then can’t constrict and impairs kidney function. “The higher you are, the harder you fall,” he said.
“Most doctors don’t screen for orthostatic hypotension unless patients complain of dizziness or lightheadedness when standing,” Dr. Juraschek said. But the American Diabetes Association recommends screening because neurological damage caused by diabetes is a common risk factor. Although a large community-based study found that 5 percent of middle-aged people had orthostatic hypotension, the disorder has been shown to affect 25 percent to 30 percent of those with diabetes.
And in a joint statement, the American Heart Association and American College of Cardiology recommended screening for orthostatic hypotension before and after starting patients on medication to lower blood pressure. People being treated with potent medications to lower blood pressure are especially at risk.
Dr. Lipsitz said, “Every patient on medication to lower blood pressure should be checked periodically for orthostatic hypotension during routine office visits.” He suggested that patients lie down for three to five minutes, then have repeated blood pressure checks done, in the first 20 to 30 seconds, after one minute and again after three minutes of standing up. He explained that when a person stands up “a half-quart of blood pools in the legs and belly,” but in older people, the increase in heart rate and blood vessel constriction needed to compensate is less effective.