Amyotrophic lateral sclerosis (also known as ALS or Lou Gehrig’s disease) is a disease that attacks the neurons (nerve cells) in your brain and spinal cord. Neurons transmit messages from your brain and spinal cord to your voluntary muscles-the ones you can control, like in your arms and legs.
At first, this causes mild muscle problems. The patient may experience difficulty walking or running, trouble writing, speech problems. Eventually, they will lose strength and will not be able to move. When the muscles in your chest fail, you cannot breathe. A ventilator may assist with breathing, but most people with ALS die as a result of respiratory failure.