Caroline Wozniacki has been diagnosed with rheumatoid arthritis – a painful condition that causes swelling and stiffness in the joints, for which there is no known cure, although medication and other treatments can relieve symptoms.

The 28-year-old tennis star has known since August, but only revealed the news today following her elimination from the WTA Finals, in which she was beaten in three sets by Elina Svitolina.

“I didn’t want to talk about it during the year because I didn’t want to give anyone the edge or anyone thinking that I’m not feeling well, because I have been feeling well,” she told media.

First noticed issues in July
Wozniacki first began to notice fatigue after Wimbledon in July when she woke up and was unable to lift her arms over her head.

“In the beginning, it was a shock. It’s obviously not ideal for anybody – particularly when you’re a professional athlete,” she said.

“You feel like you’re the fittest athlete out there and all of a sudden you have this to deal with.”

Can’t keep a champion down
However, since the diagnosis she has returned to winning ways, triumphing in the China Open earlier this month.

“You learn how to cope after matches. Some days you wake up and you can’t get out of bed and you just have to know that’s how it is, but other days you’re fine. You don’t even feel like you have it,” she said.

“Winning was huge. It also gave me the belief that nothing is going to set me back. I’m going to work with this and this is how it is, and I can do anything.”

Wants to become a role model
Ultimately, Wozniacki wants to become a role model for other people living with the pain of rheumatoid arthritis, which rarely strikes people before their 40s.

“I know there are a lot of people in the world fighting with this, and hopefully I can be someone they can look up to and say that if I can do this, then they can too,” she said.

“And you just kind of have to get together and pull each other up.”