In a Friday letter to supporters, the 76-year-old says family and friends noticed a change in him about three years ago and he could no longer ignore symptoms.
He says the diagnosis isn’t a sign to stop working but a “signal” to make “lifestyle changes” to slow progression of the chronic neurological disorder that causes movement difficulties.
“Recognition of the effects of this disease on me has been painful, and I have been slow to grasp the gravity of it,” the letter reads.
The civil rights icon also released a Northwestern Medicine letter saying he was diagnosed in 2015 and has sought outpatient care.
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Jackson runs the Chicago-based Rainbow/PUSH Coalition. He’s remained a strong voice in anti-discrimination efforts, including advocating for affordable housing, and been a fixture at protests nationwide.
Jackson declined further comment Friday.