Zac Brown Band founding member John Driskell Hopkins reveals ALS diagnosis. What is ALS?

Zac Brown Band musician John Driskell Hopkins has been diagnosed with ALS.

Hopkins, also known as Hop, revealed the "tough news" of his diagnosis in a video message on Friday, appearing alongside his bandmates and support system.

"Over the past several years, I've noticed some balance issues and some stiffness in my hands. After careful analysis by some of the country's top neurologists, I have been diagnosed with ALS," he shared.

In the video announcement, Hopkins and his bandmates revealed they have launched the Hop on a Cure foundation to support ALS research and work toward a cure.

"The technology and research surrounding ALS research has been advancing, but we still don't have a cure. Thanks so much for your prayers and support in helping us cure ALS," Zac Brown said in the clip.

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In addition to vocals, Hopkins plays guitar, banjo and ukulele for the band. He joined the group as a fill-in bass player in 2005, according to the band's official website.

Hopkins is on tour now with Zac Brown Band, with dates scheduled through November.

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Hopkins also addressed in the video what his ALS diagnosis means as far as his future with the band.

"Because my symptoms have been slow progressing from the start, we believe they will continue to be slow progressing going forward," the Zac Brown Band musician said, and added, "God willing, I plan to be rocking with these amazing people for many years to come."

What is ALS?

ALS, also known as Lou Gehrig's Disease, is a neurodegenerative disease that affects nerve cells in the brain and spinal cord, according to the ALS Association.

Early symptoms of the disease often include muscle weakness or stiffness, per the ALS Association. The effects on the brain and spinal cord can cause motor function to decrease, loss of muscle control, and loss of speech and movement. There is no cure.

According to the ALS Association, the disease can "affect anyone, anywhere, at any time." In about 90% of all ALS cases, "there’s no known family history of the disease or presence of a genetic mutation linked to ALS."

Once the onset of ALS begins in a person, the disease "almost always progresses," per the ALS Association, leading to a shortening of the person's life span. The mean survival time for people living with ALS is three to five years, with some individuals living up to 10 years or even longer.

It is very rare – less than 1% – for people with ALS to achieve "significant improvement in function lasting 12 months or longer."

Hopkins talks living life with ALS diagnosis: 'I'm ready to fight'

In an interview with People published Monday, Hopkins said he's learned to make peace with the uncertainty of his life in the wake of his ALS diagnosis.

"No one knows what the condition will be like going forward, so we can't sit around and cry about it," Hopkins told the outlet.

Hopkins added that "one of the beautiful things about (his) condition," as it stands, is that it's given him the opportunity to "make a big impact" through his artistry.

"I'm ready to go. I can still play, I can still sing, I can still make records — and I want to do all that," Hopkins said. "I'm trying to record everything I can in the event that one day I might not be able to."

Hopkins also wants to use his ALS diagnosis as a chance to model resilience and strength for his daughters Sarah Grace, 13, and twins Lily Faith and Margaret Hope, 10, who don't yet understand the "gravity" of their father's disease.

"I'm ready to fight this disease," Hopkins said. "I want to show my girls what a warrior their dad is."

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This article originally appeared on USA TODAY: Zac Brown Band founding member John Driskell Hopkins says he has ALS