What Should We Do When BP Is Low?

If your blood pressure is low, you don't always have to treat it, unless it's causing symptoms. Treatment for low blood pressure can include drinking more fluids, adjusting medicines, taking medication to raise blood pressure, and lifestyle changes.

Low blood pressure (hypotension) is a condition in which the force of blood pumping through the arteries is lower than normal. 

Blood pressure (BP) is expressed in two numbers: 

• Systolic blood pressure (the first/top number)
  • Measures the pressure in the blood vessels when the heartbeats
• Diastolic blood pressure (the second/bottom number)
  • Measures the pressure in the blood vessels when the heart is at rest between beats

What Are the Blood Pressure Ranges?

Low, normal, elevated, and high blood pressure is often defined in the following ranges: 

• Low blood pressure is 90/60 mm Hg and lower
• Normal blood pressure is less than 120/80 mmHg
• Elevated blood pressure levels between 120/80 and 139/89 
  • Considered prehypertension and means a person is at increased risk for developing high blood pressure 
• High blood pressure (hypertension) is 140/90 mmHg or more

There is no specific measurement at which blood pressure is considered too low, and it is not usually a reason for concern if a person has no bothersome symptoms. For some people, low blood pressure is normal, and in general, the lower a person’s blood pressure, the better. 

It is not always necessary to do anything when blood pressure is low, especially if low BP does not cause any symptoms. When symptoms of low BP occur, treatment depends on the specific signs and symptoms, and may include:

• Drinking more fluids
• Adjusting medicines that cause low blood pressure (never change the dose or regimen of a prescribed medication without first talking to your doctor)
• Medication to raise blood pressure
• Lifestyle changes 
  • Changing how you sit and stand up
  • Changing what and how you eat 
  • Compression stockings 

Chronically low blood pressure is usually only a medical concern if it causes noticeable symptoms such as:

• Dizziness 
• Lightheadedness
• Fainting 
• Fatigue
• Nausea
• Dehydration 
• Unusual thirst
• Blurred vision
• Inability to concentrate
• Cold, clammy, pale skin
• Depression

Extremely low blood pressure prevents the body’s organs from getting the oxygen and nutrients they need and this can lead to shock, which is a medical emergency. Call 911 and get to a hospital’s emergency department (do not drive yourself) if you notice signs of shock including: 

• Rapid, shallow breathing
• Weak and rapid pulse
• Cold and sweaty skin
• Blue skin tone

Low blood pressure may be caused by: 

• Decreases in blood volume, such as from major trauma, dehydration, or severe internal bleeding or anemia
• Some medications, such as alcohol, diuretics and other drugs used to treat high blood pressure (hypertension), heart medications such as beta blockers, Parkinson's disease medications, tricyclic antidepressants, erectile dysfunction drugs (especially when combined with nitroglycerine), and narcotics
• Prolonged bed rest
• Pregnancy, especially during the first 24 weeks when it’s common for blood pressure to drop
• Heart problems, such as abnormally low heart rate, heart valve problems, heart attack, and heart failure
• Endocrine problems, such as underactive thyroid (hypothyroidism), parathyroid disease, adrenal insufficiency (Addison’s disease), low blood sugar and diabetes
• Problems with the autonomic nervous system, such as Parkinson’s disease 
• Severe allergic reaction (anaphylaxis)
• Severe infection (septic shock)
• Neurally mediated hypotension, a disorder that causes blood pressure to drop after standing for long periods
• Nutritional deficiencies, including a low levels of vitamins B-12 and folic acid 
• Older age