Although originally diagnosed in 2012 after a tremor in his right hand caused him concerns, Dave Parker only recently revealed his diagnosis of Parkinson's disease to the general public.

"There's no fear," Parker is reported to have told the Tribune-Review. "I've had a great life... I'm 62 years old and fortunate to make it to this point."

Parker, nicknamed 'Cobra,' is known as a Pirate despite playing for five other teams, including the Cincinnati Reds. Two of his teams won the World Series: the Pittsburgh Pirates in 1979 and the Oakland Athletics in 1989. For a total of seven times, he was named to the All-Stars Team, four times as a Pirate, plus he won the National League's "Most Valuable Player" award in 1978.

Parkinson's disease is a degenerative disorder of the nervous system in which the symptoms worsen over time. Usually beginning with hand tremors, the disease may progress to a general stiffening of the limbs and slowing of movements. There is no cure for the disease, though medications that target the dopamine function of the brain and increase production of that neurotransmitter have been known to alleviate symptoms.

Muhammad Ali and Michael J. Fox are two famous people who battle the disorder. Parker's older sister also has a more advanced form of the disease, according to reports.

It is believed that specific genetic factors may play a role in the development of Parkinson's disease, but scientists still have not discovered the cause. Researchers have identified certain genetic mutations as well as genetic variations that may increase the risk of developing the disease. Scientists also believe exposure to particular toxins and certain environmental factors might increase a person's risk of developing the disease.

In 1991, Parker left his position in right field at the age of 40 with a career batting average of .290. He continued to work as a coach until retiring.