If your blood pressure is low and you feel dizzy, sit or lie down, drink fluids, and add some salt if your doctor allows. Seek care if you faint or have chest pain.
What to do
- Sit or lie down and raise your legs.
- Drink water or an electrolyte drink.
- Add salt only if your doctor says so.
- Stand slowly.
Low BP
Defined as under 90/60 mmHg.
Causes
Dehydration, medicines, heart problems, blood loss.
See a doctor
If you have frequent dizziness or fainting.
Emergency
Call 911 for chest pain, confusion, cold clammy skin or shock.
Typical low blood pressure thresholds
Low blood pressure is commonly defined as below 90 systolic or below 60 diastolic. A reading is only a problem when it causes symptoms or is a drop from the person’s usual level. Many healthy people, particularly athletes, run readings in the 90s over 50s without trouble. Orthostatic hypotension is a drop of at least 20 mmHg systolic or 10 mmHg diastolic within 3 minutes of standing.
- Sit or lie down at once if lightheaded and raise the legs above heart level.
- Drink 16 to 20 ounces (about 500 to 600 ml) of water. Rapid water intake can lift pressure within minutes in people with orthostatic drops.
- Stand up slowly and pause at the edge of the bed.
- Salt intake should not be raised without medical advice, especially in people with heart or kidney disease.
Causes worth checking
Dehydration, blood loss, pregnancy, heart rhythm problems, adrenal insufficiency, severe infection and some medicines can all lower blood pressure. Medicines include diuretics, alpha blockers, beta blockers, antidepressants and drugs for Parkinson disease. A sudden drop with chest pain, confusion, cold clammy skin, fast breathing or fainting is an emergency, since it can indicate shock. In the United States, call 911 for those signs.
Definitions and typical numbers
Low blood pressure (hypotension) is generally defined as below 90 mmHg systolic or 60 mmHg diastolic, though many healthy people, including fit athletes, run lower without symptoms. Normal is below 120/80. The key issue is symptoms: dizziness, fainting, blurred vision, nausea, fatigue and confusion. A sudden drop in blood pressure on standing, called orthostatic hypotension, is a fall of at least 20 mmHg systolic or 10 mmHg diastolic within three minutes.
Practical measures
Mild cases improve with more fluids, rising slowly, small frequent meals and in some cases a bit more salt, but only on a doctor’s advice for people with heart or kidney disease. Compression stockings help blood return. Possible causes include dehydration, blood loss, pregnancy, heart problems, endocrine conditions such as Addison disease and medications such as diuretics and alpha blockers. Severe low blood pressure with a rapid pulse, cold clammy skin or chest pain is an emergency; call 911.
Causes worth checking
Low blood pressure has many causes: dehydration, blood loss, pregnancy, heart valve disease, slow heart rate, endocrine problems such as adrenal insufficiency and hypothyroidism, severe infection (septic shock), allergic reactions and nutrient deficiencies such as low B12 or folate. Medications that lower pressure include diuretics, alpha blockers, beta blockers, antidepressants and drugs for Parkinson’s disease.
Immediate steps
If you feel faint, sit or lie down, raise your legs and drink water. Do not stand quickly. Drinking about 500 mL of water can raise blood pressure within 15 to 30 minutes in people with orthostatic hypotension. Seek emergency care for low pressure with chest pain, confusion, cold clammy skin, rapid breathing or a weak rapid pulse, which can signal shock.
Based on data from the Mayo Clinic and the American Heart Association
