Ozzy Osbourne lived with Parkinson's disease for years before his death. Here's what you need to know about the neurodegenerative disease.

Ozzy Osbourne, lead singer of Black Sabbath, has died at age 76. He said he had been previously diagnosed with a form of Parkinson’s disease linked to the gene PRKN

The three main symptoms are tremor (shaking), slowness of movement and rigidity (muscle stiffness). Subtle changes in a person’s walking pattern could be an early sign of Parkinson’s disease. Some people develop very small handwriting, a loss in their sense of smell, nerve pain or insomnia.