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This is What Causes Low Blood Pressure

An endocrinologist reveals what to know about low blood pressure. 

Having low pressure (hypotension) might not seem like a big deal, but it could indicate an underlying problem. For many people, low blood pressure goes unnoticed. Others could feel dizzy or faint or experience blurred vision. In severe cases, low blood pressure can be life-threatening. "Low blood pressure causes a lack of blood supply carrying glucose and oxygen to tissues and organ systems," says endocrinologist Brian Fertig, MD, FACE, founder and president of the Diabetes & Osteoporosis Center. "As a result, there is inadequate energy for the proper function of these tissues and organ systems." According to the National Heart, Lung and Blood Institute, low blood pressure is considered anything less than 90/60. Fertig talked with ETNT Health about what causes low blood pressure and how to help prevent it. Read on—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had COVID.


What is Low Blood Pressure?

blood pressure

"Low blood pressure should not be defined by a number per se, but rather the level below which symptoms occur for a given person," says Fertig. "Lightheadedness and dizziness while standing are the most suggestive symptoms of low blood pressure. At more severe levels, confusion and even loss of consciousness may occur. Symptoms may be worse after eating because circulation is directed to the gut, further compromising blood flow to the brain. At very low blood pressures there may be insufficient blood supply to other tissues in the body, such as the kidney, impairing function, or the heart, causing chest pain."


Why Low Blood Pressure Happens

Senior woman suffering from high blood pressure sitting at a table in her living room using a blood pressure monitor

Fertig says there are two fundamental reasons why low blood pressure occurs. "First, the heart does not pump blood adequately to the organs and tissues of the body. This may or may not be due to heart disease," he says. "Second, inadequate blood flow may be due to over dilated blood vessels from such causes as severe bacterial infection and adrenal gland or thyroid hormonal insufficiencies."  


​​How Low Blood Sugar Affects Blood Pressure

checking blood pressure

"Low blood sugar promotes the release of catecholamines (adrenaline) and cortisol from the adrenal gland to stimulate the liver to output glucose into the blood to restore normal blood sugar levels," says Fertig. 


Common Causes of Low Blood Pressure

Senior lady receiving bad news about her blood pressure from her doctor

Fertig says low blood pressure may be caused by:

  • Dehydration
  • Heart disease
  • Sepsis or severe bacterial infections
  • Blood loss (such as intestinal bleeding from a stomach ulcer)
  • Anti-hypertensive medications
  • Hypothyroidism or adrenal insufficiency, because both thyroid hormone and cortisol promote adrenaline, which constricts blood vessels
  • Pituitary tumors, which damage the function of regulatory hormones that stimulate the release of thyroid and adrenal hormones


How Can You Prevent Low Blood Pressure?

older woman is measuring blood pressure

"Adequate hydration, treatment of hormonal disorders, heart disease and infections, cautious use of blood pressure-lowering drugs, and correction of bleeding disorders" can prevent low blood pressure, says Fertig. And to ensure your health, don't miss these 101 Health Habits You Didn't Know Were Deadly.

Heather Newgen
Heather Newgen has two decades of experience reporting and writing about health, fitness, entertainment and travel. Heather currently freelances for several publications. Read more about Heather