The 26-year-old new father was "angry and frustrated and kept thinking, 'Why now?'" People magazine reported.
Experts aren't quite sure why the characteristic inflammation and nerve damage occur, but according to the National Institutes of Health, the multiple sclerosis symptoms typically include muscle weakness, numbness or tingling sensations and problems with coordination and vision. More common in women, MS is usually diagnosed between age 20 and 40, and symptoms may start out mild, come and go or become so severe that a person becomes unable to speak or walk.
There is no known cure for MS, although Osbourne says he plans to manage the disease with medication and holistic treatments, according to Time.com.
But he's not the only celebrity to receive a diagnosis or to lend his name to raising awareness for the disease. Below are 12 other famous faces who have been touched by MS.
For more on celebrity health, click here.