Stephen Hawking became paralyzed because of a progressive neurological disease called amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, which he was diagnosed with at age 21.

Quick Scoop

What actually happened?

  • In 1963, while studying at Cambridge, Hawking began stumbling, losing his balance, and having trouble with coordination.
  • Doctors ran tests and diagnosed him with ALS, a disease that attacks the motor neurons that control voluntary muscle movement.
  • As these nerve cells died, he gradually lost control of his muscles, leading over the years to near total paralysis and the need for a wheelchair.

How did ALS make him paralyzed?

  • ALS causes the brain’s signals to stop reaching the muscles, so over time walking, using hands, and even speaking become impossible.
  • Hawking’s condition progressed unusually slowly, which is why he lived for more than 50 years after diagnosis, far beyond the original prognosis of just a few years.
  • By the 1970s–1980s, he could no longer walk or use his arms independently and relied fully on a wheelchair and caregivers.

Speech loss and technology

  • In 1985, he developed a severe pneumonia, required life support, and underwent a tracheotomy, which saved his life but permanently took away his natural speech.
  • After that, he used a computer-based communication system and speech synthesizer, controlled first by hand and later by tiny movements of his cheek detected by a sensor on his glasses.

Why his story still matters now

  • Even while almost completely paralyzed, he continued to work on black holes, cosmology, and bestselling science books, becoming one of the most famous physicists of the modern era.
  • In recent years, discussions about his life often appear in forums and news as examples of resilience, disability inclusion, and how assistive technology can enable people with severe conditions to keep working at a high level.

TL;DR: Stephen Hawking did not become paralyzed from an accident; he was gradually paralyzed by ALS, a degenerative motor neuron disease diagnosed in his early 20s, which slowly took away his ability to move and speak but not his ability to think or do science.

Information gathered from public forums or data available on the internet and portrayed here.