Jennifer Millis’s coworkers always know when her son suffers a sickle-cell pain crisis. “I lose five pounds just like that,” says Millis. Despite Christopher’s countless crises, Millis says she cannot get used to them. “Every time he has a crisis is like the first time. It’s very hard to watch someone you love go through such intense pain,” she says.

For many sickle-cell patients, a pain crisis can last up to a week or more and is severe enough to require hospitalization for treatment with potent painkillers. The crippling pain described by patients tends to attack the chest, abdomen and joints, but some, like 15-year-old Donna, a Dallas high-school student, say they hurt from head to foot. “I’m talking excruciating pain all over–capitalized, underlined and circled with red!” she says. And for parents of such children, the pain comes from watching helplessly while a child suffers regularly. “There’s so little even the doctors can do,” says Millis.

There’s still no cure for sicklecell disease, an inherited blood disorder that in this country afflicts primarily African-Americans. Pain strikes when the red blood cells of sickle-cell patients stick together and clog small blood vessels. Unlike normal red blood cells that are round and pliable, in patients with the disease the cells are sickle-shaped, like crescent moons, and frequently cannot pass through arteries and capillaries. When the cells jam up blood vessels, oxygen doesn’t get to some of the organs and limbs of the body, which causes pain. This malfunction can also damage major organs, such as the kidneys, heart and liver, or cause a stroke if the vessel that’s blocked leads to the brain.

In the past, these and other complications associated with the disease shortened the lives of sickle-cell patients, many of whom didn’t survive past their early twenties. But now, thanks to recent breakthroughs and aggressive management of the disease (including blood transfusions, bone-marrow transplants and prophylactic penicillin for young children), sickle-cell patients can live long, productive lives if they know how to spot the illness and get help.