(CNN) -- Martina Navratilova was released from a hospital in Kenya Sunday after undergoing treatment for high altitude sickness developed during a failed attempt to climb Mount Kilimanjaro.
"I am feeling much better and really pleased to be going home," the retired tennis champion said as she left a Nairobi hospital, according to a news release. "It's great to know that the team have all returned safely from the mountain. I was so pleased to hear that so many of them made it to the summit despite the weather conditions."
The 27 climbers in Navratilova's group reached the base of Kilimanjaro Sunday.
Navratilova was one of several high-profile athletes talking part in a climb for charity for the Laureus Sport for Good Foundation. Laureus is an organization that seeks to raise donations for AIDS research as well as confront social problems of crime, violence, discrimination and obesity, among other causes.
Navratilova was forced to withdraw Thursday on the fourth day of the climb after becoming ill 4,500 meters up Kilimanjaro. Navratilova had to be carried down the mountain by porters.
Navratilova was initially seen by doctors at a medical center in Kilimanjaro. She was later transported to the hospital in Nairobi, where she was treated for high altitude pulmonary edema, an accumulation of fluid on the lungs.
The 54-year-old had hoped to finish 2010 on a high note by raising more than $133,000 for Laureus.
Navratilova has described this year as her "own personal 9/11." The former top women's player in the world was diagnosed with breast cancer in February, but has since been given the all-clear from the disease.
Prior to beginning the climb, Navratilova told CNN that she was "very excited" to start the challenge. She said: "I've been waiting for a year to come here."
Despite her recent health problems, altitude tests revealed that the 18-time grand slam singles champion had the lungs of a 25-year-old. However, the Laureus team was forced to face difficult weather of blizzards and mists during the climb.
Doctors say the experience will have no effect to Navratilova's long-term health, and that patients get back to full fitness after recuperating.