WEDNESDAY, July 25, 2018 (HealthDay News) -- Are you a middle-aged person who tends to feel a little woozy when you stand up?

If so, new research suggests you might need to worry more than most about developing dementia later in life.

The study focused on a condition called orthostatic hypotension -- where blood pressure drops sharply when a person stands up quickly. That can trigger sudden symptoms like dizziness, lightheadedness and blurry vision.

The condition is common in elderly people -- affecting about 30 percent of those aged 70 and older, based on a recent study. It is much less prevalent in younger adults, but when it happens there is cause for concern.

Researchers found that middle-aged people with the blood pressure condition were 54 percent more likely to develop dementia over the next 25 years, versus those without the condition.

The reasons why are not entirely clear, according to senior researcher Dr. Rebecca Gottesman. She's a professor of neurology at Johns Hopkins University in Baltimore.

But, Gottesman said, research has shown that health conditions affecting the blood vessels -- including high blood pressure and diabetes -- are also linked to a higher risk of dementia. It's thought that impaired blood flow to the brain might be why.

So in theory, Gottesman explained, repeated episodes of orthostatic hypotension could contribute to dementia risk by temporarily lowering the brain's blood supply.

On the other hand, she said, in relatively younger people the condition could be a sign of generally poorer health and greater medication use.

"Many medications -- for high blood pressure and other conditions -- can cause these drops in blood pressure," Gottesman noted.

Her team tried to account for those other medical conditions. But, she said, it's not possible to account for everything.

The study included over 11,700 U.S. adults who were followed from the late 1980s, when they were in their 40s and 50s, until 2013. At the outset, they were tested for orthostatic hypotension -- having their blood pressure measured while lying down, and then again after they stood up.

Just under 5 percent were found to have orthostatic hypotension: They had either a 20-point drop in systolic pressure when they stood up, or a 10-point decline in diastolic pressure. Systolic is pressure in the blood vessels when the heart beats, while diastolic is pressure when the heart rests.

Over the next 25 years, the study found, 12.5 percent of people with the condition developed dementia, versus 9 percent of people without the condition.

People with orthostatic hypotension were relatively older, and had higher rates of high blood pressure and diabetes. But even after the researchers accounted for that, it was still linked to a greater risk of developing dementia.

Dr. Anil Nair is director of the Alzheimer's Disease Center in Quincy, Mass.

He said the findings add to evidence that cardiovascular health matters in dementia risk.

Nair pointed out that two-thirds of the study participants with the condition also had high blood pressure -- and most of those people were on medication for it.

Since that medication can cause orthostatic hypotension, he suggested that people with potential symptoms talk to their doctor about their treatment regimen.

"Ideally, you want to control the hypertension, without over-treating it," Nair said.

Gottesman agreed, suggesting patients with symptoms should talk to their doctors about all of their medications. "If there's a simple medication change that can be made, that's worth talking about," she said.

People do not always notice the symptoms, however. In this study, it was detected through blood pressure tests. It's not clear, Gottesman said, how many people were actually experiencing symptoms in their daily lives.

So if you are on medications that can cause orthostatic hypotension, it might be wise to ask your doctor to measure your blood pressure upon standing, Gottesman advised.

Even if the underlying cause is not clear, simply knowing you have the condition can be helpful, she added.

Those patients can then pay extra attention to maintaining a healthy lifestyle, and controlling any other conditions that affect the blood vessels and heart, Gottesman said.

The findings were published online July 25 in the journal Neurology.

More information

The Alzheimer's Association has advice on healthy brain aging.