“Maxed out on the medications,” is how Bill Ezzell describes his struggle with blood pressure. It’s dangerously high even though the North Carolina man swallows six different drugs a day.

Hypertension may be the nation’s sneakiest epidemic, a time bomb that’s a leading cause of heart attacks, strokes and kidney failure, and one that’s growing worse as the population rapidly grows older.

Despite an arsenal of drugs, millions of people in the United States can’t get their blood pressure down to safe levels. Now, in a high-stakes experiment at dozens of hospitals, scientists are testing a dramatically different approach for the toughest to treat patients, by burning away some overactive nerves deep in the body that can fuel rising blood pressure.

To attempt an invasive treatment - a catheter is threaded through blood vessels in the groin up to the kidneys - reflects doctors’ frustration with a disease that too often is underrated because people with it don’t look or feel sick until a lot of damage has been done.

Pharmaceutical therapies have been the cornerstone of medicine for nearly a century, offering convenient, noninvasive treatment for countless diseases. But when it comes to some of the most stubborn chronic conditions, including diabetes, obesity and hypertension, medications too often aren’t enough.

Researchers increasingly are trying medical devices and minimally invasive surgeries to help, such as stomach-shrinking techniques that improve obesity-caused diabetes and the new hypertension experiment.

“I think we have to hit on all cylinders if we’re going to take on these very important diseases,” said Dr. Steven Nissen, chair of the Cleveland Clinic’s department of cardiology. “There are many examples where this convergence is taking place, where you push the drugs as far as you can, but when they can’t go any further, you step in with more invasive approaches.”

Cardiologists’ interest in the nerve-zapping procedure also reflects how severe the burden of hypertension is poised to become, with many middle-aged boomers already affected.

“People are living longer with hypertension, and the disease tends to get worse as you get older,” said Dr. Suzanne Oparil, a hypertension specialist at the University of Alabama, Birmingham. “The complications pile on later.”

If deadening kidney nerves sounds like a strange way to attack hypertension, consider that nerves in the body’s “fight or flight” system play a role in signaling kidney functions, which in turn help regulate blood pressure, such as by relaxing or tightening key arteries.