Sterling Marlin, winner of 10 NASCAR Sprint Cup races, revealed to ESPN.com that he has Parkinsonism.
Marlin said he began experiencing symptoms about a year ago, when he cut the knuckle on his right hand and had nerve damage.
Shortly thereafter, he had trouble completing fine-motor skills with his right hand. In time, the hand began shaking.
"Cut the knuckle real bad on (my) bird finger ... I couldn't shoot a bird. Just impossible," Marlin told ESPN's Marty Smith by phone. "It wouldn't move and I thought that was the problem. But it got healed up and I said, '... Something's still wrong.' And it kept getting worse and worse and worse, so I went to the doctor to see what the hell's going on."
He found out during the doctor's visit that he had developed Parkinsonism.
The Mayo Clinic web site states that Parkinsonism is "any condition that causes a combination of the movement abnormalities seen in Parkinson's disease -- such as tremor, slow movement, impaired speech or muscle stiffness -- especially resulting from the loss of dopamine-containing nerve cells (neurons)."
The web site also notes that "not everyone who has Parkinsonism has Parkinson's disease. Other causes of Parkinsonism can include: medications, such as those used to treat psychosis, major psychiatric disorders and nausea; repeated head trauma, such as injuries sustained in boxing; certain neurodegenerative disorders, such as multiple system atrophy and progressive supranuclear palsy; Lewy body dementia."
Marlin is one of just nine drivers to win more than one Daytona 500 race, winning in 1994 and 1995.
Marlin is retired from Sprint Cup racing but competed at the Nashville Fairgrounds Speedway over the summer.