Why Do I Feel Dizzy When I Stand Up? A Guide for Patients and Their Physicians
For the Patient You get up from the couch, and suddenly the room spins. Your vision darkens at the edges. You grab the nearest wall and wait for it to pass. If this sounds familiar, you may be experiencing orthostatic hypotension (OAH) — a condition far more common than most people realize, and one with a clear explanation. What Is It? Orthostatic hypotension means your blood pressure drops significantly the moment you stand up. Medically, it is defined as a fall of at least 20 mmHg in your top blood pressure number, or 10 mmHg in your bottom number, within three minutes of standing. That brief drop reduces blood flow to your brain — causing dizziness, blurred vision, weakness, or that unsettling "going to faint" feeling. What Should Normally Happen? When you stand, gravity pulls blood downward into your legs and abdomen. Your heart briefly receives less blood and your pressure dips. Normally, sensors in your arteries detect this instantly and signal your brain to speed up y...