High blood pressure is on the rise, and while the biggest threat is to your heart, potentially causing heart attack and stroke, recent evidence says that your brain can also suffer. That's one more big reason to get hypertension under control, say experts.

A blockbuster study recently released in JAMA found that a growing number of Americans suffer from uncontrolled high blood pressure, often referred to as the "silent killer." The JAMA data revealed that uncontrolled hypertension rose by a significant 10% in 2017-2018 compared to statistics from 2013 to 2014, according to NBC News.

"These are very sobering conclusions," said Paul Muntner, lead author of the study and an epidemiologist at the University of Alabama at Birmingham. He added that although he was surprised at the findings, earlier research has indicated that many patients are not being properly treated for high blood pressure.

Hypertension is said to be under control when the systolic or top number is lower than 140 mm Hg and the diastolic, or bottom reading, is less than 90 mm Hg. However, new guidelines recommend readings of 130/80 mm Hg. Using the revised numbers, Muntner and his colleagues found that only 19% of Americans with hypertension have their blood pressure under control.

According to Harvard Medical School, even a slight elevation of blood pressure in middle age has been associated with a 30% higher risk of dementia 20 years later. Taking blood pressure medication may mitigate that risk, said Harvard experts.

Experts say that the same mechanism that causes strokes, can damage the brain. Hypertension causes fatty plaque to build up in arterial walls, which increases your risk of a stroke. When this happens in the part of the brain that controls memory and cognition, it can lead to vascular dementia. High blood pressure damages the blood vessel of the entire body, including the brain.

"This study underscores the thinking that lowering blood pressure is likely to be an effective way to prevent cognitive impairment," said Dr. Steven Greenberg, a neurology professor at Harvard Medical School. "While we are still waiting for a breakthrough in Alzheimer's prevention, it's good to know we have common medications at hand that can help prevent dementia."

Greenberg says that if your blood pressure is higher than normal, proper treatment will likely benefit your brain as well as your heart.