Orthostatic hypotension (also called postural hypotension) is a sudden dip in blood pressure that happens when you stand up after you’ve been sitting or lying down.
When you stand, blood naturally rushes to your legs and your blood pressure drops. Your body has to work harder to keep blood moving back up to the heart by boosting your blood pressure and heart rate for a few minutes.
Symptoms of Orthostatic Hypotension
Ever feel lightheaded or woozy when you get out of bed or up from a chair?
Sometimes, it may take a moment (or several) to bring your blood pressure back to normal, and you might feel dizzy, confused, queasy, or have blurry vision until your body adjusts and catches up. Some people may even faint.
The biggest concern is that you might fall and hurt yourself if you faint. Large swings in blood pressure could also lead to a stroke if the blood flow to your brain gets interrupted often.
Causes of Orthostatic Hypotension
You're more likely to be affected when you're older. As you age, the cells in your heart and arteries that keep your blood pressure steady respond more slowly. And you're more likely to be taking medication for diabetes or heart disease, which can also play a role.
Some of the things that can lead to orthostatic hypotension are:
Dehydration. For many people, orthostatic hypotension happens only once in a while -- most often because you're low on fluids. When you're dehydrated, your body has a harder time making adjustments to control your blood pressure.
You may have mild dehydration if you've been exercising intensely, were outside in the heat or soaking in a hot tub, or are recovering from the flu, for example. Dehydration can be an ongoing concern if you have poorly controlled diabetes or if you take diuretics for high blood pressure.
Eating. Up to a third of older people are prone to dizziness after eating a large meal. Your intestine needs a lot blood to digest your food, which leaves less blood flowing in other parts of your body. When your body can't adjust for that, your blood pressure could drop and you may feel lightheaded or take a tumble. Doctors call this postprandial hypotension.
Heart disease and other medical conditions. Since the problem is related to your blood pressure, it's not surprising that people with heart disease, heart valve problems, heart failure, or an extremely low heart rate (called bradycardia) can have this kind of dizziness.
A study of elderly women found that most with congestive heart failure had a significant drop in their blood pressure when they were tilted back, then moved to an upright position. It would fall more than the blood pressure of people who didn't have heart problems or other illnesses. About half had noticeable symptoms, too, while none of the other women did, even when their blood pressure fell.
Other conditions that can affect your blood pressure or nervous system include Parkinson's disease, adrenal trouble, and thyroid problems.
Anemia (a condition where you don't have enough healthy red blood cells) or blood loss may be behind occasional dizziness.
Medications. Getting dizzy when standing can also be caused by the medication you take to treat heart conditions, including:
- ACE inhibitors
- Angiotensin receptor blockers (ARBs)
- Calcium channel blockers
- Diuretics, also known as "water pills"
Medicines that treat Parkinson's and erectile dysfunction, some antidepressants and antipsychotics for mental health, and muscle relaxants can lower your blood pressure, too.
If you take more than one of these drugs or drink alcohol while you're using them, it can raise your chance of dizziness.
How Is Orthostatic Hypotension Diagnosed?
If you’ve been getting lightheaded or dizzy when you stand up, call your doctor. Let them know right away if you’ve fainted. They can do tests to find out if you have orthostatic hypotension.
To diagnose you, your doctor might only need to take your blood pressure and pulse while you’re sitting or lying down, and then check it again after you stand up.
You have orthostatic hypotension if your systolic blood pressure drops 20 millimeters of mercury (mm Hg) or your diastolic blood pressure drops 10 mm within 5 minutes after you stand.
Your doctor may also give you blood tests that check for anemia (low red blood cells), chemical imbalances, or low fluid levels. They might recommend tests to find out if your heart is pumping properly, too.
Orthostatic Hypotension Treatment
Your doctor will work with you to figure out what's causing your dizziness and to treat any other conditions. They might adjust your medications to lessen your symptoms or recommend changes in your eating habits.
You can also ask about wearing compression stockings. They apply gentle pressure to your legs, which will help push blood back toward your heart.
It’s rare, but some people with orthostatic hypotension need prescription medications to boost their blood volume and pressure. These drugs include:
- Droxidopa (Northera)
- Erythropoiesis-stimulating agents
- Fludrocortisone (Florinef)
- Midodrine hydrochloride (ProAmatine)
Can You Prevent Orthostatic Hypotension?
To help keep your balance, stand up slowly. Avoid crossing your legs when you're sitting for a long time. Don't stand still in one place; move your feet and legs to help keep your blood flowing.
Call your doctor if it's happening regularly or more often, or when it makes you feel faint. Some people may not feel dizzy right away. It could take more than 3 minutes after you stand up. This delayed orthostatic hypotension is a milder form, but a recent study suggests that people who have it may develop more symptoms over time.
Orthostatic Hypotension vs. Orthostatic Hypertension
Orthostatic hypotension is when your blood pressure suddenly drops after you stand up. But if you have orthostatic hypertension, your BP rises after you stand.
Some researchers say orthostatic hypertension is common both in people who have high blood pressure and in those who don’t, but there aren’t a lot of studies on it.
In a young person, orthostatic hypertension may raise the chances for chronic high blood pressure later in life. In an older person, it may raise the odds for heart- or blood vessel-related problems.
One study says orthostatic hypertension usually doesn’t cause symptoms, but it’s possible to have:
- Dizziness or lightheadedness
- Heart palpitations (feeling like it’s beating too fast, pounding, or fluttering)
- Passing out (this is rare)
A study on children with orthostatic hypertension says the main symptoms in older kids are dizziness and passing out.
It’s not clear exactly what causes orthostatic hypertension, but experts think it involves your sympathetic nervous system getting activated. That’s the part of the nervous system that can boost your heart rate, blood pressure, breathing rate, and pupil size. It also causes your blood vessels to narrow and tells your GI tract when to make less digestive juice.
Some researchers say orthostatic hypertension becomes more common with:
- Advancing age
- A higher body mass index
- Chronic high blood pressure (also called primary or essential hypertension)
People with diabetes may be more likely to get orthostatic hypertension than those who don’t have diabetes. Orthostatic hypertension has also been linked to dysautonomia, a group of disorders that stem from problems with the autonomic nervous system. Your sympathetic nervous system is part of the autonomic nervous system.
If your doctor thinks you might have orthostatic hypertension, they may check for it by having you lie on your back for 5 minutes and then measuring your blood pressure with BP cuff while you’re standing. They may check your pulse rate, too.
If they’re still not sure whether you have orthostatic hypertension, they might recommend you take another exam called head-up tilt table testing. That usually means you lie on a special table that tilts you into an almost-standing position while medical staff monitors your blood pressure.
Your doctor may need to test you for orthostatic hypertension more than once to confirm the diagnosis. They might also have you wear a small device called an ambulatory blood pressure monitor. It measures and records your BP every 30 minutes or so for 24 hours.
Some experts say more research is needed to find out what types of treatments work best for orthostatic hypertension and whether some people even need medication for it.
Your doctor may recommend standard blood pressure drugs, especially if you also have primary hypertension. They might also consider prescribing BP-lowering meds called alpha-adrenoreceptor blockers, or drugs that dial down the activity of your sympathetic nervous system.