Jet Li has fought many battles on screen as an action star, but the martial artist has been keeping one battle quiet. Jet Li admitted that he is being treated for overactive thyroid 

Chinese actor Jet Li took time out from promoting his new movie "Ocean Heaven" to tell the press that he's being treated for an overactive thyroid. Li isn't the kind of guy to back down from a fight.

The Chinese action star talked about the overactive thyroid diagnosis while he was taping a talent show that he's judging in China.

The 50-year-old Kung Fu expert said he is not supposed to exercise while taking thyroid medication and it's beginning to show. He joked about gaining weight "I'm fat, I don't have the time to lose it. It's a fact!"

Hyperthyroidism, better known as overactive thyroid, changes a person's metabolism and heart rate. It is treatable with medications.

Jet Li was diagnosed with overactive thyroid in 2010. Medication was keeping the condition at bay, but it recently came back.

Jet Li may be all action on screen, but that doesn't make him immune to human ailment. He said "I'm just a regular guy, I'm not Wong Fei Hung, I'm not Huo Yuan Jia (kung fu heroes he portrays on film), I'm not a hero. I'm just like you."

Jet Li was a world class champion in martial arts when he was very young. He turned that fame into an acting career in the 1980s with such films as "Once Upon a Time in China." He also appeared in the Mel Gibson- Danny Glover film "Lethal Weapon 4." He kicked arse in "Romeo Must Die" and this year he teamed up with Sylvester Stallone, Arnold Schwarzenegger and other actions stars in "The Expendables 2."

Jet Li will continue acting but admitted "I'm in pain, but I'm not suffering. I'm happy."