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The Lowdown on Low Blood Pressure

Most people worry about having high blood pressure. But for a few people, low blood pressure (hypotension) is a big worry.

Normal blood pressure is less than 120/80 mmHg.  Low blood pressure is generally defined as a blood pressure lower than 90/60 mmHg,linked with symptoms. There is no lower limit that is unhealthy. But having a blood pressure that is too low can mean your vital organs don't get the oxygen and blood they need to work normally. Older adults may have symptoms of dizziness and light-headedness when their blood pressure drops lower than usual. But most people with blood pressure in the lower ranges are young and healthy, and have no symptoms.

What are the symptoms?

These are symptoms of low blood pressure:

  • Dizziness or lightheadedness

  • Fainting

  • Lack of concentration

  • Blurred vision

  • Nausea

  • Cold, clammy, pale skin

  • Rapid, shallow breathing

  • Tiredness (fatigue)

  • Depression

  • Unusual thirst

These are possible causes of low blood pressure:

  • Medicine. This includes medicine for high blood pressure, anxiety, heart problems, Parkinson disease, erectile dysfunction, prostate conditions, and depression. Other prescription and over-the-counter medicines may cause low blood pressure when taken with medicines for high blood pressure.

  • Standing up quickly (orthostatic, or postural, hypotension). This is a sudden decrease in blood pressure that happens when you stand up after sitting or lying down. This can cause dizziness, blurred vision, and fainting.

  • After a meal (postprandial). This is common, especially in older adults and people with diabetes. It usually occurs 1 to 2 hours after eating a high-carbohydrate meal. Doctors aren't sure of the cause, but it may be related to the body's response to carbohydrates. Or it may be tied to blood pooling in the digestive tract. Alcohol makes it worse.

  • Heart problems. These include a very low heart rate, heart attack, and heart failure.

  • Dehydration, shock, advanced diabetes, and thyroid problems

  • Genetics. Some people have naturally low blood pressure because of their genes. 

  • Pregnancy

  • Severe infection 

  • Allergic reaction

  • Vasovagal or neurocardiogenic syncope. Low blood pressure can be triggered by stressful situations or medicines. This occurs when certain nerves that help control blood pressure lose their tone. This causes fainting.

  • Severe anemia. This can be caused by low levels of iron, vitamin B-12, or folic acid.

  • Endocrine problems. These can affect the hormones that help regulate blood pressure.

  • Bleeding. Loss of blood can cause low blood pressure. This can be bleeding in the digestive tract or bleeding from trauma.

  • Nervous system diseases. These can also affect the autonomic nervous system.

Treatment

Many healthy people who have low blood pressure and no symptoms don't need treatment. Most people with long-term (chronic) low blood pressure who have symptoms can be safely treated with medicine and lifestyle changes.

These actions may help control the problem:

  • Drink more water.

  • Don't drink alcohol. It can cause dehydration. Alcohol also changes how well medicines work.

  • Slow down. You may be able to reduce lightheadedness by taking it easy when you move from lying down to standing position. Instead of jumping out of bed in the morning, sit up on the edge before standing. Wiggle your feet and move your legs. This will get your heart rate up and increase circulation.

Online Medical Reviewer: Ronald Karlin MD
Online Medical Reviewer: Stacey Wojcik MBA BSN RN
Online Medical Reviewer: Steven Kang MD
Date Last Reviewed: 1/1/2021
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