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Amyotrophic Lateral Sclerosis

Medically reviewed by Last updated on Jan 5, 2023.

What is amyotrophic lateral sclerosis?

Amyotrophic lateral sclerosis (ALS) is also called Lou Gehrig disease. ALS is a condition that damages the cells of your motor nerves. The motor nerves direct your muscles to move. These muscles gradually weaken and waste away. Over time, ALS may lead to total paralysis, including the muscles for breathing. It is a progressive disease that becomes fatal over time.

What causes ALS?

The cause of ALS is unknown, but may include any of the following:

  • An autoimmune disease causes your immune system to attack some part of your body. ALS causes the body to attack its own nerves.
  • A chemical imbalance such as too much glutamate can lead to nerve problems. Glutamate is a chemical in the brain that sends signals from one nerve to another. Too much glutamate may cause the motor neurons to die.
  • Frequent chemical exposure to fertilizers and pesticides used in gardening and lawn care may cause ALS.
  • Genetics may cause ALS. Your risk is greater if a family member has thyroid disease or an autoimmune disease.
  • Infections can damage the motor neurons.

What are the signs and symptoms of ALS?

The early symptoms of ALS include muscle weakness, tightness or stiffness, and cramps. These symptoms occur in a leg or arm. Early symptoms may instead include slurred or nasal speech, or difficulty chewing or swallowing. Symptoms worsen and spread to other parts of your body over time. You may also have any of the following:

  • A weak hand grip, dropping things often, or trouble buttoning clothes or writing
  • Tiredness more than usual, dragging one leg, or tripping when you walk
  • Arm or leg jerks while resting
  • Muscle twitching
  • Drooling or trouble breathing

How is ALS diagnosed?

ALS cannot be diagnosed with one test. Your healthcare providers may do several tests to see if another condition is causing your symptoms. You may need any of the following tests:

  • An electromyography (EMG) measures the electrical activity in the nerves that control your muscles.
  • A nerve conduction velocity test measures the nerve impulses that travel between the spinal cord and muscles.
  • A lumbar puncture, or spinal tap, may be used to check glutamate levels. Your healthcare provider will take a sample of spinal fluid to be tested.
  • Magnetic resonance imaging (MRI) pictures of your brain may show other problems that may be causing your symptoms. You will need to lie still during this test. The MRI machine contains a powerful magnet. Never enter the MRI room if you have any metal in or on your body. This can cause serious injury. Tell your healthcare provider if you have any metal implants in your body.

How is ALS treated?

There is no cure for ALS. Treatment is focused on trying to ease the symptoms and slow the rate that the disease progresses.

  • Medicines may be given to reduce the damage to the motor neurons by decreasing the release of glutamate. You may also be given medicines to ease muscle cramps, fatigue, and excessive saliva or mucus.
  • A rehabilitation program may include physical, breathing, and speech exercises.

Treatment options

The following list of medications are in some way related to or used in the treatment of this condition.

View more treatment options

What should I tell my family and friends?

Make your wishes about your care and quality of life known. You may need to speak to a social worker to know all of your options. Speak to family members about your wishes. Write them down. You can change your mind any time during the process.

Where can I find more information?

  • ALS Association
    1275 K Street NW, Suite 250
    Washington , DC 20005
    Phone: 1- 202 - 407-8580
    Web Address:

Call 911 for any of the following:

  • You have severe chest pain.
  • You suddenly have trouble breathing.

When should I contact my healthcare provider?

  • You have a fever.
  • You have chills, a cough, or feel weak and achy.
  • You are depressed and feel you cannot cope with your condition.
  • You have questions or concerns about your condition or care.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your healthcare providers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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