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Lowering blood pressure: How low should you go?

Blood pressure that is
neither too low nor too high nets better health.

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The dangers of hypertension are well documented, but low blood pressure levels can cause problems, too.

Over time, high blood pressure (also known as hypertension) wreaks havoc in the circulatory system. It is a key contributor to heart attack and stroke. That’s why millions of people each day take medicine to lower their blood pressure, with excellent results.

At the same time, the body needs to maintain a certain amount of pressure to propel oxygen-rich blood to the brain, kidneys, and other organs. Blood pressure that is too low can lead to problems such as blurry vision, dizziness, confusion, and fainting. “Finding the right blood pressure range is always a balancing act and depends on the person’s age and other health conditions,” says Dr. Randall Zusman, a hypertension expert at Harvard-affiliated Massachusetts General Hospital.

Adopting more flexible guidelines

In recognition of the trade-off between lower risk of cardiovascular disease and overall well-being, a committee of experts from the American Heart Association, the American College of Cardiology, and the American Society of Hypertension has issued an updated set of blood pressure guidelines.

The guidelines, published in the June 2015 issue of Hypertension, focus primarily on blood pressure control in people already diagnosed with coronary artery disease. The statement recommends a target blood pressure of less than 140/90 mm Hg for people at risk for heart attack and stroke, and urges a lower goal of 130/80 mm Hg for individuals who have already experienced a heart attack or other cardiovascular event. However, the overriding message from the committee is that treatment goals need to be flexible enough to account for individual needs.

Addressing the needs of older adults

In elderly people, the ramifications of overly stringent blood pressure targets can be especially dire. Why? Most older people have accumulated a certain degree of plaque buildup in their arteries that impedes blood flow. “When you lower blood pressure too much, there isn’t enough force for a sufficient amount of blood to make it through obstructed arteries to reach vital organs such as the brain,” says Dr. Zusman.

Of particular concern is that lowering blood pressure too much can hasten mental decline in some people. Another worry: a fall due to dizziness or fainting may lead to a debilitating fracture in a frail, elderly person. There is also evidence that aggressive blood pressure treatment in stroke survivors may actually put them at higher risk for a second stroke. For those reasons, the updated guidelines conclude that people who are over 80 years old might be okay with a blood pressure reading of 150/90 mm Hg.

Making the right medication choice

“We want to avoid taking a fully functional elderly person who is independent and bringing their blood pressure down to a normal range but as result making them lightheaded, dizzy, and confused because the brain isn’t getting enough blood,” says Dr. Zusman. On the contrary, blood pressure control has to take into account a person’s brain and body health and foster a good quality of life to be considered successful.

Rather than shoot for a hard target, Dr. Zusman suggests that a good treatment plan hinges on an individual’s symptoms and desires. For example, someone who is physically vigorous might want to avoid diuretics, because some of these drugs deplete the body of potassium, leading to muscle weakness and cramps. On the other hand, many people might chafe at being given a drug that could cause fatigue and mental slowdown, such as a beta blocker. In both scenarios, ACE inhibitors or calcium-channel blockers might be a better fit, depending on the person’s other health conditions.

Nondrug options

“I am a big proponent of nondrug therapy,” says Dr. Zusman. For people who do not do well on blood pressure medicines, lifestyle changes can help lower blood pressure. A strategy that incorporates a low-sodium diet, exercise, weight loss, and stress reduction can bolster the traditional pharmacological approach. 

Blood pressure goals for people with coronary artery disease

Target blood pressure (mm Hg)

Condition

Less than 150/90

Age over 80 years

Less than 140/90

Coronary artery disease
Acute coronary syndrome
Heart failure

Less than 130/80

History of

• heart attack

• stroke

• transient ischemic attack (TIA)

• peripheral artery disease (PAD)

• carotid artery disease

• abdominal aortic aneurysm

Posted by: Dr.Health

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