Civil rights leader and longtime liberal activist Jesse Jackson, 76, revealed Friday that he has been diagnosed with Parkinson's disease, the progressive neurological disease.

"My family and I began to notice changes about three years ago. For a while, I resisted interrupting my work to visit a doctor. But as my daily physical struggles intensified I could no longer ignore the symptoms, so I acquiesced," Jackson said in a statement.

"Recognition of the effects of this disease on me has been painful, and I have been slow to grasp the gravity of it. For me, a Parkinson's diagnosis is not a stop sign but rather a signal that I must make lifestyle changes and dedicate myself to physical therapy in hopes of slowing the disease’s progression."

Parkinson's disease, whose early symptoms include tremors and slow movement, has no known cure, though various treatments to mitigate its impact exist.

Jackson emerged as major political figure in the 1980s, mounting campaigns for the Democratic Party's presidential nomination in 1984 and 1988, becoming the first African-American to become a significant contender for a major party nomination. He later became a kingmaker in Democratic Party politics.