WASHINGTON (AP) – Sarcoidosis, the respiratory disease that may have contributed to the death NFL great Reggie White, usually comes and goes mysteriously, with about 95 percent of patients recovering, experts say.

Sarcoidosis is an inflammatory disease of unknown origin that usually is very mild, said Dr. Norman H. Edelman, a Stony Brook, N.Y., specialist and a scientific consultant to the American Lung Association.

“It’s a disease with an exaggerated inflammatory response to some sort of trigger,” he said Monday. “It could be an inhaled pollutant or toxin. But we don’t really know for sure.”

White died Sunday at 43. He may have died because of the disease combined with other health problems, according to a preliminary autopsy report Monday from the medical examiner in Mecklenburg County in North Carolina.

Sarcoidosis is lethal in about 5 percent of cases, and it is uncommon to die of the disease at 43, Edelman said. In about 20 percent of the cases, he said, the disease progresses and the inflammation spreads throughout the lungs, and, sometimes, to the liver, brain or heart. But even then, recovery is the most common outcome.

“The most common thing we see in patients with sarcoidosis are enlarged lymph nodes in the chest and nothing else,” Edelman said. “Eventually, in most cases, the disease just goes away and doesn’t get worse.”

Sarcoidosis is slightly more common among blacks and Scandinavians, Edelman – White was a black player. The most common effect of the disease is extreme shortness of breath.

“Typically, the symptoms are breathlessness,” the doctor said. “The inflammation in the lungs leads to scarring and it makes the lungs stiff. They must work harder to expand.”