Most people are understandably concerned about high blood pressure. But an abnormally low blood pressure can also cause problems. Although normal blood pressure is less than 120/80 mmHg, a level less than 90/60 mmHg is generally considered too low. Lower-than-normal blood pressure, or hypotension, can cause symptoms as there is too little pressure in the circulatory system to ensure adequate blood flow to the brain and other organs. There are many possible causes of hypotension, so it's important to see your doctor if you experience symptoms such as lightheadedness or fainting. Depending on the cause of your hypotension, your doctor may suggest some natural ways to counteract low blood pressure -- either alone or in combination with other treatments.
Dehydration is a common cause or contributing factor to low blood pressure. Severe vomiting and/or diarrhea, profuse sweating, poorly controlled diabetes and medications, such as water pills, are among the most common causes. Seniors are particularly prone to dehydration due to a diminished thirst reflex and medications. Dehydration, or decreased total body water, can lead to low blood pressure -- particularly if the water loss occurs rapidly or the body's ability to compensate is impaired due to an electrolyte imbalance, medications or poor kidney function. Drinking sufficient water can help stave off or reverse hypotension related to dehydration.
Diet and Nutrition
Some causes of hypotension can be addressed by changes in diet and nutrition. For example, some people experience low blood pressure after eating meals. This condition, known as postprandial hypotension, most frequently occurs in seniors. It often responds to eating smaller, more frequent meals that do not contain high amounts of carbohydrates. Drinking a caffeinated beverage, such as coffee or tea, with meals is also sometimes recommended for people with postprandial hypotension.
Increased salt intake might be helpful for certain types of hypotension, but this should only be done if your doctor recommends it. Limiting alcohol intake might also be helpful in maintaining a normal blood pressure because alcohol can provoke or contribute to dehydration.
Postural and Physical Maneuvers
Postural and physical maneuvers help some people avoid dips in blood pressure. Orthostatic hypotension is the most common cause of occasional decreases in blood pressure. With this condition, the blood pressure drops when rising to a sitting or standing position, or when standing for a prolonged period. The hypotension occurs due to diminished or delayed circulatory reflexes that normally compensate for position-related changes in blood pressure, or excess pooling of blood in the legs. Getting up more slowly or sitting on the edge of the bed for a few minutes before standing might help reduce symptoms. Physical maneuvers that help reduce blood pooling in the legs are also sometimes recommended to avoid low blood pressure related to prolonged standing. Examples include:
-- flexing the calf and thigh muscles while standing in place
-- slowly marching in place
-- rising up to tiptoes and lowering back down in place
Depending on the underlying cause of hypotension, other methods may be recommended to avoid or counteract dips in blood pressure. For example, elevating the head of the bed 10 to 20 degrees, and wearing custom-fitted elastic stockings or an abdominal binder can help prevent low blood pressure with certain conditions. Rapidly drinking 16 ounces of cold water can also help maintain blood pressure in some situations. Exercise is often helpful, although the type of exercise often must be individualized to avoid posture-related dips in blood pressure. Swimming, recumbent biking and exercises performed with sitting or lying down are examples of the type of exercise doctors might recommend.
A variety of medications can potentially cause or contribute to hypotension. Blood pressure and heart medications, and water pills are frequent culprits, but many other medicines can potentially trigger low blood pressure. Some examples include:
-- erectile dysfunction drugs (Cialis, Levitra, Viagra)
-- flibanserin (Addyi) for female hypoactive sexual desire disorder
-- muscle relaxants (Amrix, Fexmid, Kemstro, Lioresal, Robaxin)
-- certain psychiatric medications, including some antidepressants and antianxiety drugs
A number of other medications can also possibly contribute to hypotension, especially when taken in combination with heart or blood pressure medicines. For this reason, it's important to review all of your medications with your doctor if you're experiencing low blood pressure. However, do not stop taking or change the dosage of any prescription medication unless your doctor advises you to do so.
Warnings and Precautions
Occasional low blood pressure due to an obvious cause -- such as a bout of stomach flu or exercising in extreme heat without drinking fluids -- is probably nothing to worry about. However, if you experience frequent or persistent low blood pressure, or typical symptoms of hypotension, see your doctor as soon as possible. Symptoms commonly experienced with low blood pressure include:
-- dizziness, lightheadedness or fainting
-- sudden blurred vision or your vision going dark
-- breaking out in a cold sweat
-- weakness or fatigue
Many conditions can cause low blood pressure, some of them potentially serious. Seek emergency medical attention if you experience any warning signs or symptoms, including:
-- shortness of breath
-- severe or worsening chest or abdominal pain
-- racing, pounding or irregular heartbeat
-- high fever or chills
-- bloody, maroon or black stools
-- vomiting blood
-- confusion, agitation or mental slowness
-- numbness, tingling, weakness or paralysis, especially on one side of the body
Reviewed and revised by: Tina M. St. John, M.D.