How Low Can You Go: Is Low Blood Pressure Dangerous?

Posted February 27, 2023 by Smita I Negi, MD

Each time you visit a doctor’s office, your blood pressure is probably taken. This is one of the many vital sign checks that helps your provider keep tabs on your health. Just as some people are prone to heart disease based on their genetics and family history, blood pressure is an important predictor of future heart disease. While the risks associated with high blood pressure are well known, blood pressure that’s too low also can cause problems.

Blood pressure is the force of blood flow against the walls of the arteries as the heart pumps blood. It’s measured using two numbers. Systolic, or the top number, measures the pressure of your blood as your heart beats. Diastolic, or the bottom number, measures your blood pressure when your heart rests between beats.

According to the National Heart, Lung and Blood Institute, a normal blood pressure reading is when the systolic number is under 120 and the diastolic is less than 80 for a healthy adult. A reading of 90/60 is considered low. Low blood is called hypotension (say "hy-poh-TEN-shun")

Summa Health sheds light on the causes, symptoms, and types of low blood pressure and when to contact your doctor to seek treatment. Generally speaking, low blood pressure isn’t dangerous unless it causes troubling symptoms.

Cause and types of low blood pressure

1. Severe hypotension usually has a sudden onset as a result of trauma, serious infection or allergic reaction.

2. In a healthy individual, getting up quickly after you sit or lie down can cause a quick drop in blood pressure. However, in some individuals, it may be pronounced and persistent and is called Orthostatic hypotension. Dehydration can play a major role in this.
3. Neurally mediated hypotension occurs when a person has been standing for a long period of time. This type of hypotension is more common in kids and young adults or when a person has fever or viral sickness.
4. Postprandial hypotension, which occurs in older adults, causes dizziness, lightheadedness or fainting after eating. It is thought to be caused by blood pooling in the abdominal area to aid with digestion.

Other factors that can contribute to low blood pressure

• Pregnancy, especially during the first 24 weeks
• Medications like diuretics, beta blockers and antidepressants.
• Sepsis infections
• Anaphylactic allergic reactions
• Diabetes
• Anemia
• Dehydration
• A traumatic injury
• Heart conditions
• Nerve problems or a nervous system disorder
• Heat exhaustion
• Thyroid issues

People who are physically active or thin may be predisposed to low blood pressure. But for those who experience a sudden drop in blood pressure or have consistent low blood pressure readings that aren’t normal for them, this could signal a health problem.

Symptoms to watch for

Most people with hypotension have no symptoms.

Physicians look for patterns of chronic low blood pressure accompanied by one or more of the following symptoms:

• Headache
• Neck or back pain
• Nausea
• Dizziness, lightheadedness or feeling faint, tired, weak or confused
• Rapid or shallow breathing
• Blurred vision
• Dehydration and unusual thirst
• Inability to concentrate
• Cold, clammy, pale or blue skin
• Depression
• Heart palpitations, or a weak or rapid pulse

Diagnosis and work up:

Often people learn that they have low blood pressure for the first time at their physician’s office. Some may note new hypotension or chronic low blood pressure when they check BP at home.  If you have symptoms noted above associated with low blood pressure, you should see a doctor.

Your doctor will ask about your symptoms, past medical history, medicines you take as well as any prior tests. You will have a physical exam, and other tests may be done depending on the suspected cause of low blood pressure. Management would then vary based on the cause of low blood pressure.

Treatment for low blood pressure

Treatment will depend on the severity of your symptoms and could include medication adjustments, drinking more fluids to prevent dehydration, modifying your diet or increasing salt intake. If your low blood pressure is a result of a sudden change in body position, try getting up slowly. If you stand for long periods, your provider may suggest wearing compression stockings to prevent blood from pooling in your legs to aid in circulation.

When to call the doctor

If your blood pressure drops too low, your body’s vital organs may not get enough oxygen and nutrients, which can lead to a medical emergency where your tissues and cells can become damaged or die. Seek immediate medical attention if you experience cold or clammy skin, rapid breathing, skin that has a bluish color, and/or a weak or rapid pulse. 

For non-emergent symptoms, your doctor will perform tests to help identify the cause of your low blood pressure and work toward a solution.

Preventing low blood pressure and its symptoms

If you have been diagnosed with low blood pressure with symptoms, your doctor may suggest some simple ways to prevent symptoms. For example:

• Standing up slowly.
• Drink plenty of water.
• Avoid alcohol.
• Wear compression stockings.
• Consider modifying workouts to seated exercises and supine (laying down) exercises
• Hold onto something when you stand up
• Counter-maneuvers such as tensing the leg muscles or crossing your legs while standing have been shown to reduce symptoms of postural drop in blood pressure to artificially increasing the blood pressure.

If you feel dizzy or lightheaded, sit down or lie down for a few minutes. Or you can sit down and put your head between your knees. This will help your blood pressure go back to normal and help your symptoms go away.

If your doctor prescribes medicine to help prevent a low blood pressure problem, take it exactly as prescribed.