(HealthDay News) -- Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease, is a progressive disease that gradually causes its victims to lose control of their muscles. It's eventually fatal.

According to the U.S. National Institute of Neurological Disorders and Stroke, symptoms usually start as a gradual weakening of the muscles. People with ALS usually lose control of their arms and legs, and finally the muscles in their chest, which causes them to stop breathing.

There is no cure, although treatments may be prescribed to improve quality of life and reduce some of the discomfort and symptoms of ALS, including pain, depression, and difficulty sleeping.