You Asked: Why Do I Get Dizzy When I Stand Up?

It happens every so often when you get up from your desk, or hop out of bed. You stand up suddenly and are met with a feeling of wooziness. In some cases, your vision gets splotchy, or you have to brace yourself until the dizziness passes—which it always does in a matter of seconds.

Experts have a name for this fleeting condition: initial orthostatic hypotension (OH). If you experience it now and then—and research suggests most people do—rest assured that, in most cases, it’s harmless.

“These symptoms occur because there is a temporary decrease in the amount of blood—and therefore oxygen—supplied towards the brain,” says Dr. M.A. Ikram, an OH researcher and chair of epidemiology at Erasmus University Medical Center Rotterdam in the Netherlands.

It may help to think of your body and the blood circulating through it as a half-full water bottle. When the water bottle is lying on its side, the liquid inside is evenly dispersed. But flip the water bottle up, and all the liquid slides to the bottom. Something similar tries to happen whenever you stand up. “Gravity pulls down much of the blood towards your legs and lower body, leaving your heart and vessels to do more to get sufficient amounts up to your brain,” Ikram explains.

Dr. Phillip Low, a professor of neurology at Mayo Clinic in Rochester, Minn., has conducted research examining the causes and treatments for OH. “The heart is a pump, and when you stand up suddenly, the amount of blood going into the heart is reduced,” he says. “This can cause a temporary drop in blood pressure, and it takes a short amount of time for the corrective mechanisms to kick in and correct it.”

Anything that lowers your blood pressure can increase the odds that you’ll experience a spell of OH, says Dr. Rebecca Gottesman, a professor of neurology at Johns Hopkins University. She points out that young women and super-fit people—like those who train for and compete in endurance competitions—tend to have lower blood pressure scores, and so may be more susceptible to OH symptoms.

Dehydration could also raise your risks. “If you’re dehydrated, your blood volume may be lower, and so blood pressure may also be low,” Gottesman explains. If you’re sweating a lot during exercise and not consuming enough salt—which helps your body retain water, and supports adequate volume in your blood vessels—that’s a perfect recipe for bouts of dizziness after standing. Some medications, as well as pregnancy, are also associated with OH, Gottesman says.

The good news: If your periods of faintness or eye spots pass within a few seconds—and especially if you’re under age 30—you probably have nothing to worry about. Both Low and Ikram say OH is usually a benign phenomenon. Research also shows that, while common during youth and early adulthood, the incidence of OH tends to dissipate as you age.

But there are times when you shouldn’t dismiss these moments of dizziness.

One recent study of middle-aged adults—those ages 44 to 66—linked orthostatic hypotension with elevated risks for falls, bone fractures and death from any cause.

Low co-wrote a commentary on that study. He says it’s not clear why OH would result in elevated mortality risks, but it may be as simple as dizziness causing more falls and fractures. A number of studies have linked fractures—and the resulting loss of mobility—with higher rates of all-cause mortality among older adults.

Some of Gottesman’s research has also linked OH in middle-age with greater risks for dementia and cognitive decline. But she says the big unanswered question is whether OH is causing dementia, or if OH is just a symptom of some other underlying condition—like unhealthy blood vessels—that could lead to dementia and thinking difficulties. “It could be that if the brain isn’t getting enough of what it needs”—oxygen—“then over time this could contribute to dementia,” she explains. But right now that’s just a theory. More research has linked OH during middle-age to a greater risk for heart failure. But again, the associations are murky.

If you’re older than 40 and experiencing these periods of dizziness after standing, you don’t need to rush to your doctor. But you should mention it during your next appointment, Gottesman says. Your doctor can perform a few routine blood-pressure tests to ensure you’re in good health.

Regardless of your age, if the dizziness lasts more than a few seconds and is accompanied or followed by fuzzy thinking, headaches, heart palpitations, sweating or weakness, you’ll want to make that doctor’s appointment sooner than later. Your OH could be caused by a serious medical condition, including neurological disorders or some kind of blood-flow issue, Low says.

If the dizziness is short-lived and you don’t notice any other symptoms, standing up slower and drinking a little extra water may help. But you likely have nothing to worry about.