Dizziness every time you stand up usually means your body is struggling to move blood upward fast enough to keep your brain supplied. The technical name is orthostatic hypotension, and it’s defined as a drop of 20 mmHg or more in systolic blood pressure (the top number) or 10 mmHg or more in diastolic pressure (the bottom number) within moments of standing. It’s common, it has a wide range of causes, and most of them are fixable once you know what’s going on.
What Happens Inside Your Body When You Stand
When you go from sitting or lying down to standing, gravity immediately pulls about half a liter of blood downward into your legs and abdomen. Your body has a built-in correction system for this. Pressure sensors in your artery walls, called baroreceptors, detect the sudden drop in blood flow. They send a signal to your brain, which responds by tightening your blood vessels, increasing your heart rate, and making your heart contract more forcefully. All of this happens in seconds, and it’s why most people can stand up without thinking twice about it.
When that reflex is too slow, too weak, or overwhelmed by something else going on in your body, your brain briefly doesn’t get enough blood. That’s the dizzy, lightheaded, or “graying out” feeling. In some cases it can progress to fainting.
The Most Common Causes
Dehydration and Low Blood Volume
This is the single most frequent explanation, especially if the dizziness started recently. When you haven’t had enough fluids, or you’ve lost fluid through sweating, vomiting, diarrhea, or heavy exercise, there’s simply less blood available to push up to your brain. Hot weather, alcohol, and caffeine all make this worse. Many people who search for this symptom find that drinking more water and adding some salt to their diet resolves it completely.
Medications
A long list of prescription drugs can cause or worsen dizziness on standing. The biggest culprits are blood pressure medications, including beta blockers, alpha blockers (often prescribed for prostate issues), and diuretics (water pills). These drugs lower blood pressure by design, and standing up can tip that effect too far. Certain antidepressants are also common triggers, particularly older tricyclics and SNRIs like venlafaxine and duloxetine. Antipsychotic medications, Parkinson’s disease drugs, and even some SSRIs can contribute. If you started or changed a medication recently and the dizziness followed, that connection is worth raising with your prescriber.
Prolonged Bed Rest or Inactivity
Your cardiovascular system adapts to whatever you ask of it. If you’ve been sick in bed, recovering from surgery, or simply sitting for long stretches, your body gets less practiced at the rapid blood pressure adjustments that standing requires. This is why hospitalized patients are encouraged to sit up and walk as soon as it’s safe.
Age
The baroreceptor reflex slows down as you get older. A large Irish population study found orthostatic hypotension in about 6% of people in their 60s, roughly 11% of those in their 70s, and nearly 19% of people over 80. Aging blood vessels also stiffen, making it harder for them to tighten quickly when you stand.
POTS: When Your Heart Rate Spikes Instead
If your main symptom is a racing heart along with dizziness, you may have a related condition called postural orthostatic tachycardia syndrome. POTS is diagnosed when your heart rate jumps by at least 30 beats per minute within the first 10 minutes of standing, without a major drop in blood pressure. It’s most common in women between 15 and 50 and often follows a viral illness, surgery, or pregnancy. The dizziness tends to come with brain fog, fatigue, and sometimes nausea.
Other Conditions Worth Knowing About
Less commonly, dizziness on standing can point to something that needs more attention. Diabetes can damage the nerves that control blood vessel constriction, a form of autonomic neuropathy. Anemia (low red blood cell count) means less oxygen-carrying capacity in your blood, making the effect of any drop in flow more noticeable. Adrenal insufficiency, some heart rhythm problems, and neurological conditions like Parkinson’s disease can all impair the standing reflex. If your dizziness is persistent, worsening, or accompanied by fainting, chest pain, or new neurological symptoms like numbness or slurred speech, those are signs that something beyond simple dehydration is going on.
How It Gets Diagnosed
The simplest test is one you can approximate at home: lie down for five minutes, check your blood pressure, then stand and check it again at one and three minutes. Your doctor will do exactly this, looking for that 20/10 mmHg drop or any symptoms that appear on standing.
If the cause isn’t obvious, a tilt table test may be ordered. You lie flat on a motorized table for about five minutes while your heart rate, blood pressure, and oxygen are monitored. The table then tilts you upright to simulate standing, and you stay in that position for anywhere from 5 to 45 minutes while your care team watches for drops in blood pressure, heart rate changes, or symptoms. If nothing happens in that time, a medication may be given through an IV to provoke the response. It’s not painful, but the induced dizziness or faintness can be unpleasant for a few minutes.
What You Can Do Right Now
Several practical steps can reduce or eliminate the dizziness without any medical intervention.
Stand up in stages. Sit at the edge of the bed for 30 seconds before standing. Once standing, wait a moment before walking. This gives your baroreceptors time to catch up.
Drink more water and add salt. Research on patients with fainting episodes found that supplementing with about 6 grams of salt per day (roughly a teaspoon of table salt beyond what’s already in food) significantly improved blood pressure stability on standing. Increasing fluid intake supports this effect. If you have high blood pressure or heart failure, talk to your doctor before adding salt.
Use counter-pressure maneuvers. If you feel a wave of dizziness, these techniques can raise your blood pressure within seconds. Cross your legs and squeeze your thigh, abdominal, and buttock muscles. Or grip one hand with the other and pull them against each other without letting go. You can also squeeze a rubber ball in your dominant hand. Hold any of these until the dizziness passes.
Try compression garments. Waist-high compression stockings or abdominal binders in the 20 to 40 mmHg range help prevent blood from pooling in your legs and abdomen. Knee-high stockings are less effective because they miss the large blood reservoir in the thighs. These are particularly helpful for people with POTS.
Avoid triggers. Large meals divert blood to the gut and can worsen symptoms. Hot showers dilate blood vessels. Alcohol is a double hit: it’s dehydrating and it relaxes blood vessel walls. Standing still for long periods (like waiting in line) is harder on your system than walking, because walking activates the muscle pumps in your calves that push blood back up.
When the Dizziness Keeps Coming Back
If you’ve addressed hydration, salt, and standing habits and still feel dizzy every time you get up, it’s worth getting evaluated. Persistent orthostatic hypotension can increase your risk of falls and injuries, particularly as you age. It has also been linked in large studies to a higher risk of cardiovascular events over time, likely because it reflects underlying problems with blood pressure regulation. A doctor can check for medication side effects, screen for anemia or blood sugar issues, and assess whether your autonomic nervous system is functioning properly. For most people, the fix turns out to be straightforward: more fluid, more salt, slower transitions, and sometimes a medication adjustment.