Orthostatic hypotension — also called postural hypotension — is a form of low blood pressure that happens when you stand up from sitting or lying down. Orthostatic hypotension can make you feel dizzy or lightheaded, and maybe even faint.
Orthostatic hypotension is often mild, lasting a few seconds to a few minutes after standing. However, long-lasting orthostatic hypotension can be a sign of more-serious problems, so talk to your doctor if you frequently feel lightheaded when standing up. It's even more urgent to see a doctor if you lose consciousness, even momentarily.
Mild orthostatic hypotension often doesn't need treatment. Many people occasionally feel dizzy or lightheaded after standing, and it's usually not cause for concern. The treatment for more-severe cases of orthostatic hypotension depends on the cause.