Navratilova, 54, was leading a team of 27 climbers to raise funds for the Laureus Sport for Good Foundation charity, when she fell ill on the fourth day of the climb up Kilimanjaro, the highest mountain in Africa at 5,895 metres (19,341 ft).

"I am feeling much better and really pleased to be going home. I'd like to thank all the staff at Nairobi Hospital, who were wonderful, and really took care of me. The care I received during my three days in hospital was excellent," she said.

Navratilova, who won 18 Grand Slam singles titles, 31 Grand Slam women's doubles titles and 10 Grand Slam mixed doubles titles, said she was delighted that 18 of the 27 climbers reached the summit.

They included German Paralympic cyclist Michael Teuber and British Olympic badminton star Gail Emms.

"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," she said