Key Points

• Hypotension is abnormally low blood pressure. Normal blood pressure is a reading of less than120/80 mmHg. Hypotension is blood pressure that is lower than 90/60 mmHg.
• Some people have low blood pressure all the time. They have no signs or symptoms and their low readings are normal for them. In other people, blood pressure drops below normal because of some event or medical condition.
• In a healthy person, low blood pressure without signs or symptoms is usually not a problem and requires no treatment.
• The three main forms of hypotension with signs and symptoms are orthostatic hypotension, neurally mediated hypotension (NMH), and severe hypotension associated with shock.
• Orthostatic hypotension is low blood pressure that occurs upon standing up from a sitting or lying down position. NMH is low blood pressure that results from standing for too long or in reaction to severe emotional stress. Shock is a life-threatening condition in which blood pressure drops so low that the brain, kidneys, and other vital organs can't get enough blood to work properly. Shock can result from a major trauma to the body, such as serious bleeding, severe burns, heart attack, severe allergic reaction, or an infection in the blood.
• People of all ages can have hypotension. Older adults are more likely to have orthostatic and postprandial hypotension. Children and young adults are more likely to have NMH.
• Signs and symptoms of orthostatic hypotension and NMH include dizziness, blurry vision, weakness, nausea, and fainting. Both of these types of hypotension can be dangerous if a person falls because of the dizziness or fainting.
• Signs and symptoms of shock include confusion, sweating, weak and rapid pulse, and warm and flushed skin that becomes cold and clammy. If shock progresses, the person can lose consciousness. Shock can be fatal if not treated immediately.
• Treatments for orthostatic hypotension and NMH are intended to relieve symptoms and manage underlying conditions. They include medicines and use of compression socks or inflatable pants to improve circulation. Lifestyle changes also are important, such as standing up slowly, drinking lots of fluids, and learning to recognize symptoms to prevent fainting.
• Treatment for shock includes restoring blood flow to the organs through special fluids or blood injected directly into the bloodstream through a needle. Medicines can be given to raise the blood pressure or make the heartbeat stronger. Depending on the cause of the shock, other treatments such as antibiotics or surgery may be required.