Stephen Hawking is living with ALS, or amyotrophic lateral sclerosis, according to Scientific American. ALS is also known as Lou Gehrig's disease and is a motor neuron disease.
Stephen Hawking is not the normal ALS patient, as most are diagnosed after the age of 50 while Hawking was diagnosed at 21, according to Scientific American. Most live only five years after diagnosis, while Hawking has lived decades. Stephen Hawking is confined to a wheelchair and uses his cheek to operate his trademarked computer system that allows him to speak and work. He is the Center for Theoretical Cosmology's director of research at the University of Cambridge.