The 54-year-old winner of 18 Grand Slam singles titles was diagnosed with high-altitude pulmonary edema, and is recovering well, Dr. David Silverstein, a consultant in cardiology and internal medicine at Nairobi Hospital, told The Associated Press Friday.
"It is potentially dangerous when someone is at high altitude, but once brought down, recovery is quick," Silverstein told the AP.
Navratilova, who was raising money for a sports foundation, had reached 14,800 feet up the 19,340-foot Mount Kilimanjaro when her condition forced her to turn back, the AP reported.
The rest of her 27-person team, which began the climb Monday, continued on and should reach the mountain's summit on Saturday, according to the wire service.
Navratilova expressed disappointment in a statement for not being able “to complete this amazing journey.”
"It was something that I have wanted to do for so long, but it was not to be,” she said. "I am so pleased that we got it going, and I will be watching and waiting for news from the climb when they reach the summit."
Navratilova, who was diagnosed with a non-invasive form of breast cancer in April, would likely be hospitalized for two or three days and not-suffer any long-term health effects as a result of the mountain sickness, Dr. Silverstein told the AP.