Amyotrophic lateral sclerosis (ALS) is a disease of the nervous system. It leads to damage of nerve cells in the brain and spine. These nerves control muscle movement. The related muscles weaken and shrink as the disease progresses. Changes to the nerves and muscles get worse over time.

The Nervous System
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The cause of ALS is unknown. Changes in certain genes may play a role. More than a dozen genetic changes have been linked to ALS. More research will help to understand how they work in the development of ALS. Other factors like smoking or exposure to toxins may also play a role. The link to these factors is not clear.

Risk Factors

Factors that may increase your chance of ALS include:

  • Having a family member with ALS
  • Having certain genetic mutations

Military veterans have twice the risk of ALS. It is not clear why.


The first signs of ALS are minor. They may be overlooked. Symptoms can differ from person to person but may include:

  • Changes in speech
  • Tripping often while walking; general clumsiness
  • Trouble with skilled movements like grasping a pen

Symptoms will worsen over time. How fast it changes will vary from person to person. Symptoms may progress to:

  • Increasing weakness in arms and legs
  • Wrist or foot drop
  • Trouble holding things
  • Muscle twitching
  • Unpredictable and changing emotions
  • Slurred speech— dysarthria
  • Hoarseness and coughing
  • Trouble chewing and swallowing—may show as choking and gagging often
  • Weight loss due to trouble eating
  • Trouble breathing
  • Excess salivation, drooling


You will be asked about your symptoms and health history. A physical exam will be done. There are no specific tests to diagnose ALS. Symptoms will point to a problem with the nervous system. Tests will then be done to rule out other health issues that cause similar problems. Your doctor or specialists may ask for:

  • Family history
  • Imaging tests of brain and spine with:
  • Blood tests—to look for infections or other changes
  • Lumbar puncture—to look for changes in the fluid that surrounds the brain and spinal cord
  • Biopsy to closely examine muscle and nerve tissue under a microscope
  • Electromyogram—to look at problems with connection between nerve and muscle

The care team will look at the results of all the tests and types of symptoms. This will be used to diagnose ALS. However, there are other diseases with similar symptoms at start of disease. A second opinion with a nerve specialist may help to confirm the diagnosis.


There is currently no cure for ALS. A combination of treatments may help to reduce or manage symptoms. Treatment options include:


Some medicines may help to slow the progression of ALS. The medicine may be given daily or in cycles. They may also only be useful at certain stages.

Medicine may also be used to:

  • Relax muscles that are in spasm
  • Ease pain
  • Reduce heavy drooling
  • Manage depression and anxiety
  • Treat inappropriate laughter or crying

Support Care

Palliative care is a team of experts that help those with severe illnesses. They can help guide overall care according to your wishes. The team will focus on quality of life for you and your family.

ALS will affect muscles throughout the body. Chewing, swallowing, speech, and breathing can all be affected. Care will help to support the body when these changes occur. Help may include:

  • Physical therapy to ease muscle cramping and spasm.
  • Oxygen or machines to help oxygen get into the body and ease breathing. An airway will be created in base of neck to improve delivery of air to lungs.
  • Supplements to improve nutrition if eating is difficult. A feeding tube may be needed in later stages.
  • Speech therapy to improve communication. This may include electronic devices.
  • Mental health counseling and support groups can help those with ALS and their families. It may provide tool to better manage stress, depression, and anxiety.


There are no current guidelines to prevent ALS.

Revision Information

  • Reviewer: EBSCO Medical Review Board Rimas Lukas, MD
  • Review Date: 03/2019 -
  • Update Date: 09/05/2019 -