Eric Dane Reveals His Right Arm Has ‘Completely Stopped Working’ Amid ALS Battle

Eric Dane is opening up about his battle with ALS in a new sit-down with Diane Sawyer for “Good Morning America.”

ALS, or amyotrophic lateral sclerosis, is commonly referred to as Lou Gehrig's disease. It is an incurable, degenerative disease that progressively paralyzes a patient's muscles.

Diane asked what initial symptoms Eric noticed first, before his diagnosis.

The “Grey’s Anatomy” star shared, “I started experiencing some weakness in my right hand and I didn’t really think anything of it at the time. I thought maybe I had been texting too much or my hand was fatigued, but a few weeks later I noticed it got 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 and said, ‘This is way above my pay grade.'”

“I will never forget those three letters,” Eric said of having ALS. “It’s on me the second I wake up. It’s not a dream.”

He said a year and a half after his diagnosis, he has “one functioning arm.”

“My left side is functioning, my right side has completely stopped working,” he said, adding his left arm “is going.”

Dane explained, “I feel like maybe a couple more months and I won’t have my left hand either. It’s sobering.”

He told Diane he’s now “worried about my legs.”

Eric recalled a scary incident when he went on a boat trip with one if his teen daughters and realized after he jumped in the water that he “couldn’t swim and generate enough power to get back to the boat.” His daughter had to come to his rescue.

“She dragged me back to the boat,” Dane recounted. “I was, like, breaking down in tears. I made sure she got back to the water with her friend and continued on with the snorkeling with the guide. I was just heartbroken.”

Sawyer asked, “Who do you call when it hits you hard?”

Eric replied it’s his wife Rebecca Gayheart. The stars married in 2004, but separated at one point before reconciling. They share daughters Billie, 15, and Georgia, 13.

“I talk to her every day,” he said of Rebecca. Getting emotional, Dane paused before adding, “We have managed to become better friends and better parents, and she is my probably my biggest champion and most stalwart supporter, and I lean on her.”

As he faces the debilitating disease, he said, “In my heart, I don’t feel like this is the end for me. I’m fighting as much as I can. There’s so much about it that’s out of my control.”

Eric also admits the diagnosis makes him "very angry." Eric lost his father to suicide when he was 7, and he told Sawyer, “My father was taken from me when I was young, and now there is a very good chance I will be taken from my girls while they are very young.”

After the interview, Diane shared that she also sat down with Eric and his doctor to talk about what is possible for ALS patients in the next few years, and what factors could be contributing to a rise in ALS diagnoses. That portion of the interview airs on "GMA" Tuesday.