Dane -- who shot to fame amid six seasons on the hit ABC drama "Grey's Anatomy," where he played Dr. Mark Sloan, affectionately known as "McSteamy" -- said his symptoms began over one year ago, when he began to experience weakness in his right hand.

During a new interview, Eric Dane explained how he's found hope in the physician who has been leading his fight against ALS.

Now, however, the actor has shared a few more sobering updates about his health on Good Morning America. “My right side has completely stopped working,” he told the program. Dane said that he expects to lose control of the left side as well.

Dane is set to share intimate details about his diagnosis in a new "Good Morning America" interview with Diane Sawyer.

I will never forget those three letters. It’s on me the second I wake up. It’s not a dream,” he told Diane Sawyer.

Eric Dane is not backing down from his fight against ALS. The 52-year-old sat down with ABC News' Diane Sawyer in an interview for Good Morning America, where he revealed his first symptoms of the debilitating disease and how he plans to slow the effects.

The 'Grey's Anatomy' and 'Euphoria' actor spoke to Diane Sawyer alongside his doctor to explain how he plans to fight against the incurable disease.

Laura Gaynor captured this incredible video as a tornado tore across a road in Nebraska on June 16. Andrew Pihlbald, 45, who coaches a U17 boys' soccer team from Jamestown, collapsed after going into cardiac arrest during the second half of a June 4 match at Wilson High School in Wilson, New York.

Eric Dane and his doctor discussed his ALS diagnosis, symptoms and the rise in causes during an emotional 'Good Morning America' interview

In a June 16 interview with Good Morning America's Diane Sawyer, Eric Dane opened up about his reconciled relationship with wife Rebecca Gayheart. The 'Euphoria' actor said they have "managed to become better friends and better parents,