"Grey's Anatomy" star Eric Dane has died at 53 following a battle with ALS.

ALS, short for amyotrophic lateral sclerosis and also known as Lou Gehrig's disease, is a nervous system disease that affects the brain and spinal cord and causes loss of muscle control, according to Mayo Clinic.

"ALS is a nasty disease," Dane told The Washington Post in an October interview. After a fall in his kitchen, he "was in the hospital during the Emmys getting stitches put in my head."

"ALS is a progressive disease in which a person’s brain loses connection with the muscles, slowly taking away their ability to walk, talk, eat and eventually breathe," the ALS Association's website notes.

Here's what to know about the disease.