What Is Low Blood Pressure?
Low blood pressure (hypotension) means the force of blood pumping through the arteries is lower than normal.
Low Blood Pressure Symptoms
There is no specific measurement at which blood pressure is considered too low. Some people may not feel anything when they have low blood pressure and it is not usually a reason for concern as long as a person has no bothersome symptoms.
For some people, low blood pressure is normal, and in general, the lower the blood pressure reading, the better.
Chronically low blood pressure is usually only considered a medical concern if it causes noticeable symptoms. Symptoms of low blood pressure may cause you to feel:
- Dizzy
- Lightheaded
- Faint
- Nauseated
- Fatigued
- Unusually thirsty
- Dehydrated
- Unable to concentrate
- Vision is blurry
- Cold, clammy, pale skin
- Depressed
When Low Blood Pressure Is an Emergency
Extremely low blood pressure can be serious because it prevents the body’s vital organs from getting the oxygen and nutrients they need which can lead to shock, a medical emergency. Call 911 and get to a hospital’s emergency department (do not drive yourself) if you feel signs of shock including:
- Rapid, shallow breathing
- Weak and rapid pulse
- Cold and sweaty skin
- Blue skin tone
What Causes Low Blood Pressure?
Low blood pressure (hypotension) may be caused by:
- Decreased blood volume, such as from major trauma, dehydration, or severe internal bleeding or anemia
- Certain medications
- Drugs used to treat high blood pressure (hypertension)
- Diuretics
- Heart medications such as beta blockers
- Erectile dysfunction drugs (especially when used in combination with nitroglycerine)
- Medicines used to treat Parkinson's disease
- Tricyclic antidepressants
- Narcotics
- Alcohol
- Prolonged bed rest
- Heart problems
- Abnormally low heart rate
- Heart attack
- Heart failure
- Heart valve problems
- Pregnancy
- It’s common for blood pressure to drop. especially during the first 24 weeks
- Problems with the autonomic nervous system, such as Parkinson’s disease
- Endocrine problems
- Underactive thyroid (hypothyroidism)
- Parathyroid disease
- Adrenal insufficiency (Addison’s disease)
- Low blood sugar and diabetes
- Severe infection (septic shock)
- Severe allergic reaction (anaphylaxis)
- Neurally mediated hypotension, a disorder that causes blood pressure to drop after standing for long periods
- Nutritional deficiencies, including a lack of vitamins B-12 and folic acid
- Older age
How Is Low Blood Pressure Diagnosed?
Blood pressure is measured by medical professionals with a device called a sphygmomanometer that includes a cuff that is placed around the arm and inflated with air until no blood can flow through the brachial artery. The air is then slowly released until blood starts to flow through the arm again, creating a pounding sound that can be heard by placing a stethoscope close to the elbow.
Blood pressure is expressed in two numbers:
Systolic blood pressure (the first/top number) | measures the pressure in the blood vessels when the heart beats |
Diastolic blood pressure (the second/bottom number) | measures the pressure in the blood vessels when the heart is at rest between beats |
Low, normal, elevated, and high blood pressure are usually defined in the following ranges:
Blood Pressure Type |
Blood Pressure Levels (mm HG) |
---|---|
Low blood pressure | 90/60 |
Normal blood pressure | less than 120/80 |
Elevated blood pressure (at risk for high blood pressure) | between 120/80 and 139/89 |
High blood pressure (hypertension) | 140/90 or more |
What Is the Treatment for Low Blood Pressure?
Treatment may not be needed for low blood pressure (hypotension) if it causes no symptoms. When treatment is needed, it depends on the specific signs and symptoms, and may include:
- Drinking more fluids
- Medication to raise blood pressure
- Adjusting medicines that cause low blood pressure
- Never change the dose or regimen of a prescribed medication without first talking to your doctor
- Lifestyle changes
- Changing what and how you eat
- Modifying how you sit and stand up
- Compression stockings
From
Heart Health Resources
https://www.heart.org/en/health-topics/high-blood-pressure/the-facts-about-high-blood-pressure/low-blood-pressure-when-blood-pressure-is-too-low
https://www.nhlbi.nih.gov/health-topics/low-blood-pressure