Ask Dr. K: Pay attention to prehypertension

DEAR DOCTOR K: My doctor says I have prehypertension. If it’s “pre,” then I don’t need to worry about it, right?

DEAR READER: Prehypertension is a blood pressure reading of 120-139/80-89 mm Hg. That’s the gray zone between normal blood pressure (below 120/80) and hypertension, or high blood pressure (above 140/90). We know that hypertension is dangerous. It increases your risk of heart disease, stroke, kidney disease and impaired vision.

Doctors first coined the term “prehypertension” because they found evidence that having prehypertension puts you at higher than average risk for developing hypertension later on. Having prehypertension meant, at a minimum, two things. First, it was even more important for you than for the average person to make the lifestyle changes that reduced your risk of getting hypertension. Second, it meant your blood pressure needed to be measured more frequently.

Now, new studies reveal that prehypertension also poses health risks of its own. It may independently increase your risk of having a stroke. For example, researchers analyzed 19 high-quality studies that focused on the links between prehypertension and stroke. The studies included more than 750,000 people who were followed for 36 years. The researchers broke down the participants into two groups:

• Low-range prehypertension: Blood pressure between 120/80 and 129/84.

• High-range prehypertension: Blood pressure between 130/85 and 139/89.

People with high-range prehypertension had a 95 percent higher stroke risk compared with people with normal blood pressure. Those in the low range had a 44 percent higher risk.

So far, doctors don’t recommend that people with prehypertension take medications.

Instead, people with prehypertension should focus on lifestyle changes: low-salt diets, healthy weight and regular exercise. These can lower your blood pressure to the normal range without having to take medications.