Grand Slam tennis champion Martina Navratilova is in good condition after being hospitalized with high-altitude pulmonary edema -- a form of mountain sickness -- after attempting to climb Mt. Kilimanjaro, Africa's highest peak.
The 54-year-old was hiking with a 27-member group from the charity Laureus Sport for Good Foundation, which hoped to continue to the summit by Saturday, according to the Associated Press
Navratilova's condition is common among high-altitude climbers as fluid accumulates in the lungs. She was diagnosed by Dr. David Silverstein, a consultant in cardiology and internal medicine at Nairobi Hospital.
"It is potentially dangerous when someone is at high altitude, but once brought down, recovery is quick," Silverstein told the AP. "Martina is doing well and will continue to do well."
Porters helped Navratilova down the 19,340-foot mountain and drove her to the Kilimanjaro Christian Medical Centre. She was later flown to the Nairobi Hospital for further tests and treatment after abandoning the climb.
The group had faced heavy snows and mist since they began their ascent last Monday.
"I'm disappointed not to be able to complete this amazing journey," Navratilova said in a statement. "It was something that I have wanted to do for so long but it was not to be."
The tennis pro had never climbed more than 12,000 feet and when she reached 14,800 feet, she began to feel unwell. She told the AP she was "petrified" of not reaching the summit "because then the whole world will know."
In high-altitude pulmonary edema, fluid develops in the lungs, either in the lung tissue itself or in the space normally used for gas exchange. The body is deprived of oxygen and cannot normally function.
The first signs are difficulty walking or inability to keep up, a tight feeling in the chest, congestion and a cough. The climber can also feel extreme fatigue and weakness and exhibit poor judgment.
"It's remarkable, once you get patients down from the mountains to a lower elevation, they feel 100 percent better," said Dr. Benjamin Honigman, professor of emergency medicine at University of Colorado School of Medicine and director of the Altitude Research Center. "If it's caught in time, they do very well."
High Altitude Pulmonary Edema (HAPE) -- which affects an estimated 3 to 5 percent of climbers in Colorado's 11,000-foot peaks -- is much less dangerous than high altitude cerebral edema, according to Honigman. "That can have devastating outcomes."
The condition happens more in the winter than in the summer and is more common among those with colds or respiratory infections.
HAPE doesn't affect all climbers, but those who are predisposed get a leakage of fluid in the air spaces in the lungs. Those who have had it before, are more likely to get it a second time.
"Athletes like Navratilova tend to exercize at a higher level and increased exercise can predispose them to high altitude pulmonary edema," said Honigman.
HAPE usually comes on after a few days, rather than in the first 12 hours like acute mountain sickness.
"You are feeling more shortness of breath, more breathing issues and seem to be having a more difficult time than your colleagues," he said. "The third night, you begin to hear rattling in the lungs and the fluid."