When Marc Sims walked into his regular barbershop for his weekly haircut, he wasn't looking to change his life.

He was surprised to see a blood pressure machine—and several people he didn't know.

His barber, Eric Muhammad, explained that his Inglewood shop had teamed up with the Smidt Heart Institute for a study that brought blood pressure testing and pharmacists into barbershops.

Then he offered to take Marc's blood pressure.

"No, I'm cool," said Marc, now 43. He was fit and healthy—he didn't need to bothered every time he came in for a trim.

Marc planned on ducking further inquiries by sticking to a 6:30 am appointment to avoid the pharmacist. Eric wasn't fooled. He convinced the study staff to come in early to meet with Marc.

Black men in the US have higher-than-average rates of hypertension, but Marc showed no obvious risks for high blood pressure beyond being black and male. When he finally let Eric check his blood pressure, though, the results were stunning: 175/115.

Marc's blood pressure was high enough to put him at risk of heart attack and stroke. It was a wake-up call.

Read: Barbershop-Based Study Lowers Blood Pressure in Black Men

As part of the study, a pharmacist in the barbershop worked with him and his doctor to prescribe blood pressure medication and talk about lifestyle changes that could bring his hypertension down.

Marc took the medications and got serious about lifestyle changes. He added healthier foods to his diet, quit smoking, gave up alcohol, and started exercising. For the duration of the 6-month study, Eric took Marc's blood pressure every week when he came in for his haircut.

Thanks to his hard work and Eric's encouragement, Marc is now managing his blood pressure solely through the lifestyle changes he's made—he no longer needs blood pressure medication.

"I knew I had to stay focused," Marc says. "I have an 8-year-old son, and I have to be here for him."

He's one of many success stories from the study.

The New England Journal of Medicine recently published the study's findings. Nearly 64% of the study participants who worked with their barber and a pharmacist at the barbershop were able to lower their blood pressure to levels considered healthy the American College of Cardiology.

In the Newsroom: Hypertension Study Based in African-American Barbershops Honored

Uncontrolled hypertension is a leading cause of premature death among black men. Dr. Ronald G. Victor, director of the Hypertension Center, started a pilot program in Dallas to address blood pressure in barbershops. When he came to the Smidt Heart Institute, he expanded the program throughout Southern California.

"We needed an environment where men felt very comfortable," Dr. Victor says. "It's a social hub, but it's not exclusive. Men can relax and talk about whatever is on their mind."

Not only are black men disproportionately affected by hypertension, they're also the least likely population to seek treatment.

Eric says that's one reason he was so enthusiastic about the study. He'd hosted other single-day awareness events about hypertension, but Dr. Victor's study aimed to find a long-term solution for treating high blood pressure.

"High blood pressure has cost the lives and health of a lot of good men," Eric says. "What's different about this study is it looks at bringing down blood pressure by using the men's community—their friends, family, and support group."

In Discoveries: Cutting Blood Pressure

Marc is now an evangelist for blood pressure testing too. He says his message for all black men is simple: "Get your blood pressure taken. You think you're fine? Let's see if you're fine. You don't know until you take it. It might save your life."