What is ALS?

Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease and motor neuron disease, is a progressive neurologic disease that affects nerve cells in the brain and spinal cord resulting in muscle weakness and impaired physical function.


Signs and symptoms of ALS may include:

  • Difficulty walking or lifting, tripping, or dropping things
  • Weakness in your arms and legs
  • Muscle cramps, painless muscle twitching or muscle spasms
  • Slurring of speech or ‘thick’ sounding speech
  • Difficulty speaking and swallowing
  • Difficulty holding your head up or maintaining good posture
  • Difficulty breathing

ALS symptoms are variable from person to person. The symptoms can start in the muscles of the hands and feet, or those that help with speaking or swallowing.

When the symptoms start in the hands and feet, it can cause difficulty in managing everyday activities such as dressing and washing. If legs are affected first it can cause difficulty with walking or falls.

When the disease starts in the speaking and swallowing muscles (known as bulbar ALS) it will affect communication and eating.

Over time, ALS will eventually affect all muscles of the body including arms, legs, speech, swallowing, chewing and breathing. Muscles become progressively weaker over time. ALS does not usually affect bowel or bladder control or your senses such as vision and hearing. It may also affect your ability to think and make decisions.

Who is at risk for ALS?

Risk factors for ALS include:

  • Gender – Slightly more men than women develop ALS
  • Age – ALS symptoms most commonly begin in mid-life between the ages of 40 and 70 (average age is 55)
  • Heredity – Approximately 5-10% of patients inherit the disease. The remaining 90-95% have what is known as sporadic ALS, meaning no known genetic link

Because the genetic risk of acquiring ALS is small, it is possible that some people with ALS acquired the disease through certain environmental factors. Established environmental factors that may contribute to the risk of ALS include military service and smoking. Other risk factors are being explored.