• Posted August 13, 2025

Tennis Star Monica Seles Reveals Her Battle With Myasthenia Gravis

Tennis great Monica Seles is speaking out about her battle with myasthenia gravis, a rare autoimmune disease that weakens muscles.

The 51-year-old, who won nine Grand Slam titles and was inducted into the International Tennis Hall of Fame, said she first noticed symptoms while playing casual tennis with family.

“I would be playing with some kids or family members, and I would miss a ball. I was like, ‘Yeah, I see two balls.’ These are obviously symptoms that you can’t ignore,” Seles told The Associated Press.

“And, for me, this is when this journey started," she added. "And it took me quite some time to really absorb it, speak openly about it, because it’s a difficult one. It affects my day-to-day life quite a lot.”

Seles was diagnosed three years ago but decided to speak out ahead of the U.S. Open, which begins Aug. 24, to raise awareness of the condition, also known as MG.

Myasthenia gravis is a chronic disease that causes weakness in voluntary muscles, according to the U.S. National Institute of Neurological Disorders and Stroke. It can occur at any age but is most common in women under 40 and men over 60.

For Seles, symptoms included double vision and weakness in her arms and legs. “Just blowing my hair out ... became very difficult,” she told The AP.

“When I got diagnosed, I was like, 'What?!’ ” Seles said. She had never heard of MG until her doctor referred her to a neurologist. She is now partnering with the Dutch immunology company argenx on its “Go for Greater” campaign to help others learn about the condition.

Seles compared living with the disease to adapting on the tennis court.

“I had to, in tennis terms, reset — hard reset — a few times,” she said. She noted her earlier challenges — immigrating to the U.S. as a teen, sudden fame and returning to competition after being stabbed at a 1993 tournament in Germany.

"Being diagnosed with myasthenia gravis: another reset. But one thing, as I tell kids that I mentor: ‘You’ve got to always adjust. That ball is bouncing, and you’ve just got to adjust,’ ” Seles added. “And that’s what I’m doing now.”

More information

The Mayo Clinic has more on myasthenia gravis.

SOURCE: The Associated Press, Aug. 12, 2025