Amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (a-mi-o-TROE-fik LAT-ur-ul skluh-ROE-sis), or ALS, is a nervous system (neurological) disease that causes muscle weakness and impacts physical function.

ALS is often called Lou Gehrig's disease, after the famous baseball player who was diagnosed with it. ALS is a type of motor neuron disease that causes nerve cells to gradually break down and die. In the United States, ALS is sometimes called motor neuron disease.

In most cases, doctors don't know why ALS occurs. A small number of cases are inherited.

ALS often begins with muscle twitching and weakness in an arm or leg, or sometimes with slurring of speech. Eventually, ALS can affect your ability to control the muscles needed to move, speak, eat and breathe. ALS can't be cured and eventually leads to death.

Symptoms Causes Risk factors Complications

Early signs and symptoms of ALS include:

  • Difficulty walking, tripping or difficulty doing your normal daily activities
  • Weakness in your leg, feet or ankles
  • Hand weakness or clumsiness
  • Slurring of speech or trouble swallowing
  • Muscle cramps and twitching in your arms, shoulders and tongue
  • Difficulty holding your head up or keeping a good posture

The disease frequently begins in your hands, feet or limbs, and then spreads to other parts of your body. As the disease advances, your muscles become progressively weaker. This weakness eventually affects chewing, swallowing, speaking and breathing.

However, ALS doesn't usually affect your bowel or bladder control, your senses, or your thinking ability. It's possible to remain actively involved with your family and friends.

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