Lightheadedness on standing is called orthostatic hypotension, when blood pressure drops briefly. Dehydration and some medicines are common causes.
What it is
Orthostatic hypotension is a drop in blood pressure of at least 20 mm Hg systolic or 10 mm Hg diastolic within 3 minutes of standing.
Causes
- Dehydration and heat.
- Blood pressure or antidepressant medicines.
- Anemia, heart problems and diabetes.
- Bed rest and pregnancy.
- Parkinson’s disease.
What helps
Stand slowly, drink water, avoid long standing, eat smaller meals and wear compression stockings.
See a doctor if
Dizziness is frequent, you faint or have chest pain.
Emergency
Dizziness with weakness on one side or speech trouble can signal a stroke. Call 911.
Common
It affects about 6 percent of the general population and 20 percent of older adults.
What it is
Feeling lightheaded when standing up is common, caused by a brief drop in blood pressure called orthostatic (postural) hypotension. When you stand, gravity pulls about 500 to 800 milliliters of blood into your legs and abdomen. The body normally compensates within seconds by tightening blood vessels and raising heart rate. If this reflex is slow, blood flow to the brain falls briefly, and you feel dizzy, see spots or may faint. It is defined as a drop in systolic blood pressure of at least 20 mmHg or diastolic of at least 10 mmHg within three minutes of standing.
Causes
- Dehydration from not drinking enough, sweating, vomiting or diarrhea.
- Medications: blood pressure drugs, diuretics, antidepressants, drugs for Parkinson’s disease, erectile dysfunction pills and alpha blockers.
- Standing up too fast after lying or sitting.
- Heat and hot showers.
- Alcohol.
- Pregnancy.
- Anemia, low blood sugar and heart problems such as arrhythmias, valve problems or heart failure.
- Nervous system disorders, such as Parkinson’s, diabetes neuropathy, and multiple system atrophy.
- Prolonged bed rest.
- Older age. About 20% of adults over 65 and up to 30% of those over 75 have orthostatic hypotension.
- Adrenal insufficiency.
What helps
- Stand up slowly. Sit on the edge of the bed for a minute first.
- Drink water, about 2 liters a day, and 16 ounces right before standing in the morning.
- Increase salt intake only if a doctor advises.
- Avoid alcohol and long hot showers.
- Cross legs, tense leg muscles or do heel raises before standing.
- Wear compression stockings or an abdominal binder.
- Eat smaller meals, since large meals can lower blood pressure.
- Review medications with your doctor.
See a doctor if
Episodes are frequent, last, lead to fainting or falls, or come with chest pain, shortness of breath, heart palpitations, confusion or vision changes. A doctor can check blood pressure lying and standing, run blood tests, ECG and other tests. Medicines such as fludrocortisone, midodrine or droxidopa may be prescribed.
Emergency
Call 911 for fainting with chest pain, severe headache, weakness on one side, trouble speaking or a head injury from a fall.
Common
Brief dizziness on standing happens to most people at some time and is usually harmless.
Blood pressure physiology
When a person stands, about 500 to 800 ml of blood shifts to the legs, and the body quickly constricts vessels and speeds the heart to keep blood pressure stable. Orthostatic hypotension is defined as a drop in systolic pressure of at least 20 mmHg or diastolic 10 mmHg within 3 minutes of standing. It affects about 6 percent of the general population and about 20 percent of people over 65. Causes include dehydration, heat, blood loss, anemia, diabetes, Parkinson disease, heart conditions and medicines such as diuretics, alpha blockers, antidepressants and blood pressure drugs. Drinking 16 ounces of water quickly can raise blood pressure within minutes. Stand slowly, cross your legs, tense leg muscles or wear compression stockings. Fainting, chest pain, shortness of breath or confusion needs urgent medical help.
Based on data from the Mayo Clinic and the American Heart Association
