Why You May Feel Dizzy or About to Pass Out When Standing or Climbing Stairs

If your vision gets dark as you stand up, or you get a head rush when climbing stairs, it may be a drop in blood flow to your brain, a type of hypotension. Or it may feel like you're going to pass out, a condition known as syncope. Learn what's behind these conditions.

​Read more:​ The 6 Big Health Risks of Low Blood Pressure — and What to Do About It

The condition that occurs when you feel dizzy standing up after sitting or lying down is known as orthostatic hypotension, according to the Mayo Clinic. Another name for it is postural hypotension. Dizziness is the most common symptom and usually lasts for just a few minutes. Other signs and symptoms may include:

• Blurred vision or seeing spots
• Weakness
• Nausea
• Confusion
• Passing out and falling

"When you stand up quickly, blood can still be pooled in the bottom part of your body," explains James Winger, MD, an associate professor of family medicine at the Loyola University Medical Center, Maywood, Illinois. "Receptors in your body automatically tell your heart to beat faster and your blood vessels to squeeze down to force more blood up to your brain. When this reflex is too slow, you can start to feel dizzy and you may even pass out."

Orthostatic hypotension is usually not serious if it happens only occasionally, does not last long and does not cause you to pass out. "The most common cause is medication," says Dr. Winger. "Another common cause is dehydration. People at highest risk are seniors with chronic diseases on multiple medications."

Orthostatic hypotension is most common after age 56, according to the Mayo Clinic. Common drugs that may contribute include heart and blood pressure medications, muscle relaxants and medications that treat Parkinson's disease. Diseases that can contribute include diabetes and diseases of the heart and nervous system. Other risk factors include heat exposure, a long period of bed rest and drinking alcohol.

"If you pass out, or feel like passing out during or after exercise, like climbing stairs, it may be more serious than orthostatic hypotension," Dr. Winger says. "Syncope after exercise is a red flag. It may be a sign of a problem with your heart."

Syncope caused by a heart problem is called cardiac syncope, according to the Cleveland Clinic. If you have cardiac syncope, the problem is still that not enough blood is getting to your brain, but the cause may be an abnormal heart rhythm (arrhythmia), poor blood flow to your heart muscle, an abnormal heart valve or heart failure​.​

According to the Cleveland Clinic, the most common sign of syncope is passing out. You may also have symptoms before passing out. Lying down or sitting with your legs elevated can prevent you from passing out if you have these warning symptoms:

• Feeling lightheaded or dizzy
  
• Feeling drowsy or groggy
• Changes in vision
• Headache
• Heart palpitations
• Nausea

If you have symptoms of syncope with exercise, like climbing stairs, be sure to tell your doctor. You may need tests of your heart functions, such as an electrocardiogram (ECG) or an imaging study called an echocardiogram, says the Cleveland Clinic.

"You should always tell your doctor if you pass out or fall," Dr. Winger says. "Tell your doctor if you have orthostatic hypotension that occurs frequently, or if the symptoms last more than a few minutes. Your doctor may check your blood pressure sitting and after standing up.

The American Heart Association says that anyone who has syncope symptoms should have a medical evaluation. Tests may include an exercise stress test (ECG during exercise). In some cases, increasing fluids and salt intake may reduce symptoms. For others, drugs for high blood pressure may need to be reduced or changed. Other treatments may depend on diagnostic testing.

​Read more:​ Is Low Blood Pressure Sneaking Up on You Late in Life?