Actor Eric Dane has opened up about his battle with amyotrophic lateral sclerosis (ALS) and is revealing the one symptom — the very first one — he experienced, but didn’t think much of at the time it happened.

The former “Grey’s Anatomy” star, 52, revealed this important fact to Diane Sawyer in a new interview on “Good Morning America” Monday.

“I started experiencing some weakness in my right hand, and I didn’t really think anything of it at the time,” Dane explained.

“I thought maybe I had been texting too much, or my hand was fatigued,” he added. “But a few weeks later, I noticed it had gotten a little worse.”

“So I went and saw a hand specialist, who sent me to another hand specialist. I went and saw a neurologist, and the neurologist sent me to another neurologist, who said, ‘This is way above my pay grade,’” he continued.

It took nine months for Dane to find out what was really going on, but that’s when the “Euphoria” actor was diagnosed with amyotrophic lateral sclerosis, commonly referred to as ALS or Lou Gehrig’s disease.

During the interview with Sawyer, Dane revealed his sobering reality — his right hand has “completely stopped working,” which leaves him with “one functioning arm.” He also noted that his left arm is “going” and feels like he only has “a few more months” of function in that arm.

And now he’s worried about his legs.

ALS, which is a degenerative neurological disorder, is a condition where symptoms worsen over time, according to the National Institutes of Health.

The NIH notes that ALS causes motor neurons, a type of nerve cell in the brain and spinal cord, to deteriorate, causing the muscles to weaken and eventually leads to paralysis. This takes away a person’s ability to move, speak, or even breathe.

There is currently no cure.

Dane, a father of two teenaged daughters, first publicly revealed to People in an exclusive interview that he had been diagnosed with ALS, also known as Lou Gehrig’s disease, in April.

“I have been diagnosed with ALS,” he shared at the time. “I am grateful to have my loving family by my side as we navigate this next chapter.”

EmilyAnn Jackman is a trending reporter for Penn Live. She handles the top trending topics on social media, as well as breaking stories in pop culture and entertainment news that goes viral on a national…