The tennis pro was taken off the climb up the 19,341 ft. Tanzanian mountain after developing high altitude pulmonary oedema, a condition marked by fluid in the lungs. Navratilova, 54, was one of 27 climbers making the trek to raise money for Laureus Sport for Good Foundation charity, which uses sports as a means to combat social challenges like substance abuse and mental health problems.
"I'm disappointed not to be able to complete this amazing journey," she said in a statement released Friday as she recovered at Nairobi Hospital in Kenya. "It was something that I have wanted to do for so long, but it was not to be. 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 [on Saturday]."
The Mt. Kilimanjaro climb began Dec. 6 and is expected to wrap up on Dec. 11.