It sounds simple. With proper attention to blood sugar and diet, a person with diabetes can go a long way toward staying healthy. But it’s not simple. Many people with diabetes risk illness and even death by leaving their disease untreated. The vast majority of people who are referred to the diabetes center where I work have excellent access to health care and good doctors. Yet their diabetes is out of control.

A 58-year-old executive came to my office several years ago, referred for what his primary-care doctor called “noncompliance with his diabetes regimen.” The patient was at least 20 pounds overweight, he did not follow his diet and he rarely checked his blood sugar, saying he didn’t understand how and when to do it. His wife nagged him so often about his health that he called her the “chief of the diabetes police force.” He came to my office unwillingly and feeling sheepish, the way people do when they intend to go to the gym but never get around to it.

Ignoring diabetes may seem as irresponsible as smoking cigarettes or driving drunk. But in many ways it’s more understandable. For one thing, the disease moves so slowly that people with diabetes often feel perfectly fine. About one third of those with type-2 diabetes–more than 5 million people–don’t even know they have it.

For those who know or suspect they have diabetes, denial can be a powerful obstacle to treatment. Because diabetes has genetic roots, many people at risk have already watched a relative go blind or lose a leg. Not knowing that treatments have improved dramatically over the past decade, these people assume, wrongly, that such complications are inevitable. Patients have asked me, “What’s the point of giving up the food I love if I’m going to go blind anyway?”

Then there’s the intimidating prospect of a lifetime of vigilance. To properly care for their disease, people with diabetes may have to check their glucose between sets of tennis. Or excuse themselves from a business meeting to eat a snack. Taking care of diabetes “is not for an hour, it’s not for a week, it’s not just for Wednesdays,” a patient once told me. “Diabetes never takes a vacation.” The relentlessness of the regimen creates in many a sense of isolation and fatigue. When no one else in the restaurant needs to worry about health when the food is slow to arrive, staying motivated to care for the disease gets harder and harder.

To make matters worse, people with diabetes get insufficient support from the U.S. health-care system. Diabetes centers around the country are closing because many insurers do not reimburse for preventive treatment. And many doctors, with their growing caseloads, don’t have time to give people with diabetes the attention they need. Too often they tell patients to lose weight or get more exercise without ensuring that real lifestyle changes are taking place.

People with diabetes need more than preprinted menus and one-time lessons in finger pricks. They need long-term, individualized educational and nutritional counseling. Not only do people with diabetes need to learn the difference between an English muffin and a bagel; they need to learn about various glucose meters and medications–and then get comfortable using them. And then there’s the matter of long-term maintenance. Some people manage diabetes well on their own. But others need ongoing attention and an understanding ear when they fall off the wagon. There’s good news, though. In the three years since he visited our center, that 58-year-old executive has brought his blood-sugar level down to normal. He’s stopped gaining weight and has no complications from diabetes. Now he’s telling his friends and family that while treating diabetes is no fun, it’s doable in an active, healthy life–and it’s better than the consequences of ignoring it.