Why do I feel dizzy when I stand up too fast?

Feeling dizzy when you stand up too fast is common. It’s often related to orthostatic hypotension (also called postural hypotension), which is a brief drop in blood pressure when you change position.

Why it happens

1. Blood briefly pools in your legs and abdomen: When you stand, gravity pulls some blood downward.
2. Less blood returns to the heart for a moment: That can cause a short drop in blood pressure.
3. The brain gets less blood flow briefly: This can cause dizziness, lightheadedness, or blurry vision.
4. Your body corrects it quickly: Sensors called baroreceptors detect the change and help raise your heart rate and tighten blood vessels so the feeling usually passes within seconds.

Common triggers

• Dehydration
• Heat such as hot showers or hot weather
• Standing up after lying down for a long time
• Certain medications such as blood pressure medicines, diuretics, and some antidepressants

What can help

• Stand up in stages: sit on the edge of the bed or chair first
• Drink enough fluids
• Tighten your leg muscles before standing

When to get checked

If this happens often, lasts more than a few seconds, or you faint, see a clinician. Get urgent care if it comes with chest pain, shortness of breath, weakness, or other concerning symptoms.