The short answer: Standing moves blood toward your legs, and some blood pressure medicines weaken the reflex that corrects the drop or reduce your fluid volume. The 2011 consensus definition of orthostatic hypotension is a fall of at least 20 mm Hg systolic or 10 mm Hg diastolic within 3 minutes. Report it to your prescriber.

What happens to blood pressure when you stand up?

When you stand, gravity moves blood from the upper body to the legs. For a moment the heart has less blood to pump, so pressure falls. MedlinePlus says the body normally corrects this quickly, and most people never notice.

A 2017 consensus panel gives the normal numbers. In healthy people, systolic pressure falls by less than 10 mm Hg, diastolic pressure rises by about 2.5 mm Hg, and heart rate rises by 10 to 20 beats per minute. The main driver is norepinephrine released from sympathetic nerve endings.

Blood pressure medicine can interfere in two ways:

  • A weaker reflex. The panel says beta blockers, verapamil-type calcium channel blockers, carvedilol, and central drugs such as clonidine and guanfacine can limit the normal heart rate rise.
  • Less blood volume. The panel names the blood volume depletion that comes with diuretics. The lisinopril label adds that sweating, dehydration, vomiting, or diarrhea can cause a large fall in pressure.

The result can be a prolonged drop on standing. Our guide to what blood pressure is too low covers low readings in general.

What counts as orthostatic hypotension?

The 2011 consensus statement is still the standard. As quoted by the 2017 panel, it defines orthostatic hypotension as a sustained fall of at least 20 mm Hg systolic, 10 mm Hg diastolic, or both, within 3 minutes of standing.

Three details matter:

  • Dizziness alone counts as a finding. The CDC STEADI falls tool treats lightheadedness or dizziness on standing as abnormal, even when the numbers do not reach 20/10.
  • No symptoms does not mean no drop. MedlinePlus says most people with orthostatic hypotension have no symptoms.
  • A higher starting pressure can change the cutoff. In neurogenic orthostatic hypotension (a nerve-related form) with lying pressure of 150/90 mm Hg or more, the panel says 30/15 may fit better. It also notes that some people drop only after 3 minutes.

It is not rare. In a 2023 JAMA analysis of 29,235 hypertension trial participants (mean age 69), 9% had it at the start.

Which blood pressure medications are linked to it?

The best class comparison we found is a 2021 PLOS Medicine review of 69 placebo-controlled trials with 27,079 people. An odds ratio of 2 means about double the odds of placebo. A range that crosses 1 means no clear effect.

  • Alpha blockers (such as doxazosin). Odds ratio 1.87 (95% CI 1.33 to 2.64) across 7,250 people, most treated for prostate symptoms. The doxazosin label warns of postural hypotension within a few hours of a dose, and fainting risk after the first dose or a dose increase. In its hypertension trials, 19% reported dizziness against 9% on placebo.
  • Beta blockers. Odds ratio 7.76 (2.51 to 24.03) across 1,097 people. That range is very wide, so the true size is uncertain.
  • Central drugs. Odds ratio 2.40 (1.55 to 3.74). These 3 trials enrolled people with heart failure, cor pulmonale, or delirium, not typical hypertension patients.
  • Diuretics. The review had too few trials to pool. The hydrochlorothiazide label still lists orthostatic hypotension as an adverse reaction, and says alcohol, barbiturates, narcotics, or other blood pressure drugs can make it worse.
  • ACE inhibitors and ARBs. Odds ratio 1.22 (0.54 to 2.74), no clear effect. The lisinopril label says symptomatic postural hypotension is usually not seen, but it should be expected in people low on fluid or salt. The losartan label also warns about people low on fluid or salt.
  • Calcium channel blockers. Odds ratio 0.89 (0.49 to 1.65), no clear effect.

Many of these trials excluded older adults, so the authors say real-world effects may be larger. They also caution that drugs in one class may not behave alike. For alpha blockers, timing can matter too: see morning or night dosing.

Does tighter blood pressure control make it worse?

Not on average, based on the trials. A 2021 Annals of Internal Medicine meta-analysis looked at 18,466 participants in 5 trials of blood pressure goals. Intensive treatment slightly lowered the odds of orthostatic hypotension (odds ratio 0.93, 95% CI 0.86 to 0.99). The authors concluded it should not be viewed as a reason to avoid or scale back treatment.

The 2023 JAMA analysis found similar benefit either way. Intensive or active treatment lowered cardiovascular disease or death in people with orthostatic hypotension at the start (hazard ratio 0.83) and in those without it (0.81).

These are group results with limits. The 2021 tests began seated, skipped the first minute after standing, and had no data on falls or fainting. They do not tell you whether your own regimen is right. Our article on stopping blood pressure medication covers that decision.

How do you check for it at home?

This checklist comes from the clinician-facing CDC STEADI tool and the 2017 panel, which focused on neurogenic orthostatic hypotension. Treat it as notes for your prescriber, not a diagnosis.

  1. Pick your times. The panel suggests first thing in the morning before morning medicines, when you feel symptoms, and at bedtime, for several days.
  2. Get help if you are unsteady. The panel warns that some people can fall when standing suddenly. It says to stand with help as needed.
  3. Lie down for 5 minutes with the cuff on. If you cannot lie down, sit for at least 5 minutes. The panel accepts this as an alternative in clinics.
  4. Take a resting reading. Write down blood pressure and pulse.
  5. Stand up, then take a reading at 1 minute. Note any symptoms.
  6. Take another reading at 3 minutes.
  7. Lie down if you feel faint or dizzy. The losartan patient information says to lie down and call your doctor right away.
  8. Do the math. Subtract each standing reading from the resting one. Flag a fall of 20 systolic or more, or 10 diastolic or more, and flag any dizziness.
  9. Keep a diary. The panel suggests at least 7 days of readings before a visit, and another week after any treatment change.

A normal result does not end the question. The panel says meals, hydration, time of day, and medicines all affect it.

What should you tell your prescriber, and when is it urgent?

Dose changes go through your prescriber, so do not stop a medicine or change a dose on your own. The lisinopril label asks patients to report lightheadedness, especially in the first few days. Bring your diary, and include:

  • When symptoms start in relation to each dose, and any new medicine or dose increase.
  • Any fainting, falls, vision changes, or leg weakness on standing (from the panel's screening questions).
  • Everything else you take, including antidepressants, which the panel names as a common cause. The doxazosin label also warns about PDE-5 inhibitors such as those used for erectile dysfunction.
  • Recent vomiting, diarrhea, heavy sweating, or alcohol use.

MedlinePlus says to seek treatment right away or call 911 if low blood pressure makes someone pass out. It says to call your provider right away for dizziness or lightheadedness, fainting, chest pain, shortness of breath, an irregular heartbeat, black or maroon stools, or a fever above 101°F (38.3°C). If you have fainted, ask your prescriber right away what to do about your next dose.

The NHLBI says to call 9-1-1 for signs of shock: cold, sweaty skin, rapid breathing, a bluish skin tone, or a weak, rapid pulse.

The panel also lists blood volume loss and chronic illness as causes, so your medicine may not be the whole story. If your dizziness does not fit a pattern, symptom.md can help you think it through.

The bottom line

Dizziness on standing can mean your body is not correcting a pressure drop. Alpha blockers have the clearest evidence, and the beta blocker signal is strong but imprecise. Trials do not show that tighter control causes it overall. Measure lying and standing, write it down, and take the log to your prescriber.

Last updated: November 2026. This article is for informational purposes only and does not constitute medical advice. Talk to your prescriber before changing any blood pressure medicine.