Hypotension
Key points
- Low blood pressure is an abnormal condition where a person's blood pressure (the pressure of the blood against the walls of the blood vessels during and after each beat of the heart) is much lower than usual, which can cause symptoms such as dizziness or lightheadedness.
- When the blood pressure is too low, there is inadequate blood flow to the heart, brain, and other vital organs.
- Another common cause type of low blood pressure is orthostatic hypotension, which results from a sudden change in body position, usually from lying down to an upright position.
- Bed rest and assistance with daily activities as needed until the condition improves.
Alternative names
Blood pressure - low; Low blood pressure
Definition
Low blood pressure is an abnormal condition where a person's blood pressure (the pressure of the blood against the walls of the blood vessels during and after each beat of the heart) is much lower than usual, which can cause symptoms such as dizziness or lightheadedness.
Considerations
When the blood pressure is too low, there is inadequate blood flow to the heart, brain, and other vital organs.
A blood pressure level that is borderline low for one person may be normal for another. The most important factor is how the blood pressure changes from the normal condition. Most normal blood pressures fall in the range of 90/60 mm Hg to 130/80 mm Hg, but a significant change, even as little as 20 mm Hg, can cause problems for some people.
Common Causes
Low blood pressure is commonly caused by drugs such as the following
- Medications used for surgery
- Anti-anxiety agents
- Treatment for high blood pressure
- Diuretics
- Heart medicines
- Some antidepressants
- Narcotic analgesics
- Alcohol
Other causes of low blood pressure include the following:
- Dehydration
- Heart failure
- Heart attack
- Changes in heart rhythm (arrhythmias)
- Fainting
- Anaphylaxis (a life-threatening allergic response)
- Shock (from severe infection, stroke, anaphylaxis, major trauma, or heart attack)
- Advanced diabetes
Another common cause type of low blood pressure is orthostatic hypotension, which results from a sudden change in body position, usually from lying down to an upright position.
Home Care
Follow prescribed therapy. Bed rest and assistance with daily activities as needed until the condition improves.
Call your health care provider if
Call your local emergency number (such as 911) if someone is unconscious. If trained in basic life support (BLS) or advanced cardiac life support (ACLS), check the person's ABCs (airway, breathing, and circulation). If the person is NOT breathing or has NO pulse, begin CPR.
Written and revised by
David Cohen, M.D.
Our doctors write and review articles for accuracy and keep them up to date.
health.am provides general information, not medical advice. Always consult a qualified health professional about your own health.