Hypotension: The Little-Known Blood Pressure Issue

Everyone has heard of hypertension or knows of someone struggling with high blood pressure. The disease, which affects almost half of all U.S. adults, can lead to serious health problems, including heart attack or stroke.

Few, however, know much about hypotension or low blood pressure. Unlike hypertension, it doesn’t get much attention, and many who have the condition may not realize they have it. 

There’s a reason for the disparity in awareness, says Maria Delgado-Lelievre, M.D., a cardiologist at the University of Miami Health System.

Though both are related to the blood flow in our body, they are actually on different ends of a continuum.

Hypertension is inherited, though lifestyle factors affect it, and the disease has well-known risks.

Hypotension, on the other hand, is variable in expression, its onset, and causes. It often tends to be benign and can be caused by various factors. 

“They’re not opposites of each other,” explains Dr. Delgado-Lelievre, who is also the founder and director of the Comprehensive Hypertension Center at UHealth.

“Hypertension is a disease. It stays with you. It is treatable but not curable.

“Hypotension is not like that. The causes are multiple, from life-threatening events (such as wound shot, severe bleeding) to transient causes (such as dehydration, drugs, postural changes), and when you address those, the blood pressure returns to the normal range.”

However, there are patients where hypotension is a common event and is more related to vascular abnormal response, such as postural orthostatic tachycardia or POTS.

Hypotension — when the force of blood flow against the artery walls is too low — can be defined as a blood pressure reading below 90/60 mmHg.

(A blood pressure below 120/80 mmHg is considered healthy. Anything above that is considered high.) As mentioned above, there are several kinds of hypotension, however. 

For example, postprandial hypotension and postural hypotension (or orthostatic hypotension) are often bring the patient to the emergency department due to the symptoms.

The cause of blood pressure drop is one of the factors that differentiates them.

In postprandial hypotension (PPH), your blood pressure drops after eating, likely because the blood vessels can’t maintain normal blood pressure during food digestion. This is a prevalent cause of transient hypotension, affecting about 40% of patients over 65 years old, especially those with a history of cardiovascular disease. 

On the other hand, postural hypotension is related to the changes in blood pressure when patients stand up after sitting or lying down. This is a common cause of hypotension and is more frequent after 65 years of age and in patients with cardiovascular disease, especially hypertensives on blood pressure medication. 

The prevalence of each increases with age. A meta-analysis of meal-related drops in BP found that more than 40% of older adults have suffered from this, though it’s less common among younger people.

Orthostatic hypotension affects 20% of older adults but only 5% of middle-aged adults.

There’s a sound medical explanation for this. As you grow older, the vessels that carry blood age, too. “They don’t respond at the same speed as when you’re younger,” Dr Delgado-Lelievre says. “They get stiffer with age. Vascular disease is common in the elderly.”

Since the COVID-19 pandemic, Dr. Delgado has been seeing more patients of all ages with hypotension and postural hypotension, similar to orthostatic tachycardia syndrome (POTS). POTS is caused by autonomic nervous system dysfunction, which regulates bodily functions such as sweating and blood circulation. People with POTS sometimes develop hypotension.

Some people with low blood pressure don’t know they have it.  “They’re walking around without any symptoms,” she says. “They don’t require treatment, and they’re fine. That’s just how they’re made.”

However, chronic low blood pressure, especially if caused by an underlying health problem, can damage the brain and other organs. So it’s important to be aware of hypotension’s most common symptoms: dizziness/lightheadedness, fatigue, fainting, nausea, lack of focus, and blurred vision. 

People can also have low BP with symptoms but not be aware of them.

Nocturnal hypotension occurs when a person is sleeping, unaware of changes in his body or vision. But “if the drop is severe enough, it compromises blood circulation to the brain,” she explains.

This can result in impairment of vascular circulation in the brain and particularly in the eyes, which increases the risk for ischemic events or changes in eye health. 

Though some symptomless individuals can function out of normal range without problems or consequences, many might experience an episode or a series of them. When this happens, it’s time to seek medical help.

“People who are asymptomatic don’t show up in my clinic,” she explains. “They’re walking around without problems. The ones who come [to me] have experienced something that concerns them.”

Some medical conditions can also be an underlying factor for hypotension:

• Parkinson’s disease
• heart valve problems
• endocrine issues
• Addison’s disease
• diabetes
• anemia
• malnutrition
• depression

Then there are the life-threatening scenarios, such as septic shock when bacteria enter the bloodstream, an allergic reaction, and significant trauma (think gunshot wound) or internal bleeding.

The cause determines the treatment.

One common explanation for low BP is hypertension medication used incorrectly.

The wrong dosage can slow the force of the blood flow too efficiently. A physician, however, can easily adjust that. Other drugs, including anti-depressants and erectile dysfunction drugs, lower blood pressure, too.

There are ways to manage hypotension if you suffer from symptomatic episodes that don’t require medication:

• Add salt to your diet. While sodium is the bad guy when it comes to heart disease and stroke, it nevertheless is essential to maintaining your electrolyte levels. Just don’t overdo it.
• Wear compression socks. Dr. Delgado-Lelievre recommends them, especially for her older patients. By putting pressure on your blood vessels, they can bring up your BP.
• Stay hydrated. When you get dehydrated, your blood supply drops, lowering blood pressure. This is particularly important in the heat and humidity of South Florida.
• Limit alcoholic beverages. They tend to dehydrate you.                   
• Learn the best way to get out of bed or to stand up from a seated position. Dr. Delgado-Lelievre tells her older patients to take their time in sitting up or rising so the body can adjust to the change in position. 
• Exercise. It promotes blood flow.

Ana Veciana-Suarez is a regular contributor to the University of Miami Health System. She is an acclaimed author and journalist who has worked at The Miami Herald, The Miami News, and The Palm Beach Post.

Tags: blood pressure hypotension, blood volume, Dr. Maria Delgado, drop in blood pressure, treat high blood pressure