Hopkins said he plans to continue playing with the band as long as he is able.
John Driskell Hopkins, a founding member and bassist for the country music group Zac Brown Band, says he has been diagnosed with ALS.
Hopkins, 51, announced the diagnosis in a video posted to the band's official YouTube channel on Friday. He told viewers he had some "tough news" to share.
ALS, or Amyotrophic lateral sclerosis, sometimes known as Lou Gehrig’s disease, is a disease that targets the nervous system, making muscles weaken and limiting physical function.
Hopkins said for several years he had noticed issues with his balance and that his hands would become stiff. He said he met with doctors and "after careful analysis by some of the country’s top neurologists, I have been diagnosed with ALS."
"Because my symptoms have been slow progressing from the start," Hopkins said, "we believe they will continue to be slow progressing going forward."
The video ends with a text line to donate to ALS research and a message to "Hop on a Cure." Hopkins is sometimes called "Hop."
"God willing," Hopkins said, "I plan to be rocking with these amazing people for many years to come.”
Zac Brown Band is currently touring and dates are listed through November, according to their website.
Kalhan Rosenblatt is a reporter covering youth and internet culture for NBC News, based in New York.
