Two hours a day, Jeff Davis works at staying alive. He inhales a succession of medications, runs on a treadmill and sometimes performs breathing exercises that produce gurgly, crackling sounds.
It's tedious work, crammed into a life that includes a full-time job as a machinist and leisure time with his wife and two young children in the horse country north of Westminster. But it has paid dividends: A generation ago, few people with cystic fibrosis lived past their teens - and Davis is 35.
If there's a miracle in this story, it's that Davis is fairly typical, having soldiered through childhood with a closet full of medications and parents who spent untold hours thumping his torso to keep his lungs clear.
"They told my parents that if I lived to be a teenager, that would be about it," Davis said during a recent visit to Johns Hopkins Hospital's adult cystic fibrosis clinic, established a decade ago. "The fact they even have an adult clinic is pretty amazing."
Affecting 30,000 people in the United States alone, cystic fibrosis is an inherited disease that causes the body to produce thick, sticky mucus that can clog the lungs and damage the pancreas, interfering with the body's ability to absorb nutrients. As a result, victims are prone to dangerous respiratory infections and struggle to gain weight.
In the early 1960s, the median survival age was 10 years. Desperate parents watched frail children cough their way through life and eventually succumb to infections, even malnutrition.
But a steady progression of drugs, medical devices and improvements in disease management has made it possible for patients not only to survive longer, but also to attend college, have careers and raise families. By the early 1980s, median survival had risen to 21 years. Today, it is 37.
"We now expect children to live into adulthood and to be healthy as well," said Dr. Peter Mogaysal, director of the cystic fibrosis center at the Johns Hopkins Children's Center. "Several decades ago, most people with CF died in childhood, and it was the exception to have patients live to be an older adult."
To achieve that, patients face steep challenges - not just lung infections and the likelihood that they will someday die of the disease, but daily treatments that can sideline them from things they'd rather be doing.
"We're talking about the late teens, early 20s, a time when all of us are trying to get careers, find spouses and think about having a family," said Dr. Michael Boyle, who runs the adult clinic at Hopkins. "They're doing all those things - plus spending an hour or two maintaining their health."
Until the 1990s, there weren't enough adult survivors to justify a clinic of their own. Since the clinic's founding, the caseload has grown from 40 patients to 200.
"I went to medical school here, trained in adult medicine and saw one cystic fibrosis patient the whole time," said Boyle, a pulmonologist who graduated from Hopkins in 1990.
But a few years later, while subbing for a colleague at the pediatric clinic, Boyle noticed something odd: several young adults looking curiously out of place in a waiting room where youngsters sat on pint-sized chairs and played with toys.
In 1996, Boyle established one of the first adult cystic fibrosis clinics. Today, there are 96 in the U.S. accredited by the Cystic Fibrosis Foundation, which has funded virtually all the drug development that has led to survival gains.
Survival, though, is no easy task.
Patients can become resistant to the antibiotics that treat and prevent infections. They fight side effects that can include hearing loss and dizziness. They can lose lung function if they start skipping treatments. And a quarter develop diabetes and require insulin.
All these issues were evident one afternoon as Boyle and colleagues met to review patient histories before their appointments.
A man who had recently lost his brother to the disease worried about whether he was doing enough to stay healthy. A woman with a 2-year-old child had been coughing up blood.
A young man developed osteoporosis - the combined effect of medication, chronic inflammation and digestive problems. A college student had to connect herself to a feeding tube at night to keep her weight above 100 pounds.
Whatever their symptoms, patients suffer from a single underlying problem. By inheriting a mutant gene from each parent, they are saddled with a defective protein that sits on the surface of cells lining the lungs, airways and pancreas.
The protein is supposed to maintain a proper balance of salt and water, both inside and outside the cells. But instead, the salt concentrates in the cells, and the mucus lining the airways becomes thick and sticky - the bane of a patient's life.