Low blood pressure

Alternative Names

Low blood pressure; Blood pressure - low; Postprandial hypotension; Orthostatic hypotension; Neurally mediated hypotension; NMH

What is Low blood pressure

Low blood pressure is a condition characterizing by dizziness and fainting. In rare cases, low blood pressure can be fatal. Although blood pressure varies from person to person, a blood pressure reading of 90 millimeters of mercury (mm Hg) or less systolic blood pressure (the top number in a blood pressure reading) or 60 mm Hg or less diastolic blood pressure (the bottom number) is generally considered low blood pressure.

Signs and symptoms

Symptoms of low blood pressure may include:

• Blurry vision
• Confusion
• Dizziness
• Fainting (syncope)
• Light-headedness
• Sleepiness
• Weakness

Possible complications

The most common complications of low blood pressure are shock and injury from falls due to fainting.

For older adults, falls are especially dangerous. Fall-related injuries such as a broken hip can dramatically impact a person's quality of life.

Severe hypotension starves your body of oxygen that can damage the heart, brain and other organs. This type of hypotension can lead to death if not immediately treated.

What causes

There is no exact cause of low blood pressure, but the possible causes may be linked to the following conditions:

• Pregnancy
• Hormonal problems such as an underactive thyroid (hypothyroidism), overactive thyroid (hyperthyroidism), diabetes or low blood sugar (hypoglycemia)
• Intake of non-prescription medications
• Overdose of high blood pressure drugs
• Heart failure
• Heart arrhythmias (abnormal heart rhythms)
• Widening or dilation of the blood vessels
• Heat exhaustion or heat stroke
• Liver disease

Prevention

There are certain steps to prevent or decrease your symptoms of low blood pressure. They are:

• Avoiding alcohol
• Avoiding standing for a long time (if you have NMH)
• Drinking plenty of fluids
• Getting up slowly after sitting or lying down
• Using compression stockings to increase blood pressure in the legs

Treatment

Low blood pressure in a healthy person that does not cause any problems usually does not require treatment.

It is very important to get immediate treatment if you have signs or symptoms of low blood pressure. The treatment depends on the cause of your low blood pressure. Severe hypotension caused by shock is a medical emergency. You may be given blood through a needle (IV), medicines to increase blood pressure and improve heart strength, and other medicines such as antibiotics.

If you have orthostatic hypotension caused by medicines, your doctor may change the dose or switch you to a different drug. You should not stop taking any medicine before talking to your doctor. Other treatments for orthostatic hypotension include increasing fluids to treat dehydration or wearing elastic hose to boost blood pressure in the lower part of the body.