Understanding ALS

The more you learn about ALS, the better prepared you’ll be. Remember, in addition to doing your own research, speaking regularly with your healthcare provider(s) will help you make the most informed decisions moving forward.

What is ALS?1,2

Amyotrophic lateral sclerosis (ALS) is a disease that affects the parts of your nervous system that control your muscles, like those used for speaking, eating, moving, and breathing. It is progressive, which means the symptoms continue to get worse over time. ALS symptoms can be very different for different people based on which parts of the body are affected first. You may have heard ALS referred to as Lou Gehrig’s Disease.1,3

How do I say it?

amyotrophic ay-my-uh-TROH-fik

|

lateral LAT-uh-rul

|

sclerosis skluh-ROH-sis

Is there a cure for ALS?

Currently, there is no cure for ALS. However, it’s important to ask your healthcare provider(s) about treatment options.

How does ALS affect the body?1

ALS starts in the brain and spinal cord. It affects nerve cells called motor neurons.

Motor neurons extend from the brain to the spinal cord and from the spinal cord to voluntary muscles throughout the body.

These cells send messages from the brain to the muscles that control movements like walking, holding objects, talking, swallowing, and even breathing.

In ALS, these messages stop being sent and the brain loses control of the muscles, making it hard to move and stay independent.1

Not everyone will have the same symptoms

ALS symptoms can happen at different times for different people. However, over time, most people with ALS will feel muscle weakness and experience loss of movement.1,3

Who does ALS affect?

If you have ALS, it’s important to remember you’re not alone. ALS affects people of all ages, races, and ethnic backgrounds. ALS is the most common of the motor neuron diseases (MNDs), which is a wider group of disorders that can lead to loss of physical function.4

About 5000+ people in the United States are diagnosed with ALS each year.5

On average, a new case of ALS is diagnosed every 90 minutes.5

How do you get ALS? Is ALS genetic/hereditary?

The contributing factors for developing ALS are not fully understood. However, in some rare cases, ALS may be inherited. There are 2 types of ALS1:

Genetic ALS

  • Those with a family history may be more at risk of getting ALS
  • Caused by mutations in genes passed down through families

Sporadic ALS

  • Makes up 90% of all ALS cases
  • Happens at random
  • Is not connected to having a family history of the disease

Research suggests many factors can contribute to the loss of motor neurons in the brain, which may increase the chances of developing ALS. These factors may include6:

  • A genetic defect
  • Destabilized molecules in brain cells
  • A defect that prevents normal cell movement and division
  • A defect to the “power generator” inside cells that gives them energy
  • Environmental factors, such as toxins or viruses
  • Overactivity of the immune system
  • A phenomenon known as oxidative stress, caused by harmful particles called free radicals and the body’s inability to counteract their effects
  • A defect in the metabolic process that fuels muscles
  • An imbalance between healthy and unhealthy cells

What are the symptoms of ALS?

ALS looks different for everybody, but some symptoms may include3,7:

Head and neck

  • Trouble speaking
  • Too much saliva
  • Hard to swallow

Lungs

  • Shortness of breath
  • Breathing problems
  • Waking at night because of breathing difficulties

Upper body

  • Weak hands
  • Can't move your arms easily
  • Muscle spasms in your upper body
  • Trouble getting dressed or with personal hygiene
  • Difficulty writing
  • Hard to make food

Lower body

  • Tripping often
  • Stairs are hard to use
  • Weakness in feet

Here’s an example of how ALS may show up in different cases

Two people newly diagnosed with ALS may experience their disease in very different ways. For instance, one person may have trouble grasping a pen or lifting utensils, while the other may experience a change in the sound of their voice.8

ALS can progress differently for each person. Some people may first notice changes in their speech or swallowing, while others may feel weakness in their hands, arms, legs, or feet. Not everyone experiences the same symptoms or in the same order. However, over time, most people with ALS will face increasing muscle weakness and loss of movement.8

Because of the individual nature of ALS, it’s extremely important that you speak with your healthcare provider(s) about all symptoms you may be experiencing.

How is ALS progression tracked?

Several clinical measures have been developed to monitor ALS. Some of these include:

Function-Based Questionnaires9

Doctor-administered questionnaires ask people with ALS to rate how well different muscle groups are working, based on a sliding scale. The individual scores for each muscle group are then tallied, providing a high-level assessment of overall muscle function.

The most well-known questionnaire is called the ALS Functional Rating Scale-Revised (ALSFRS-R).

Strength Measurements9

Since muscle weakness is a major feature of ALS, measuring strength over time can help your healthcare provider(s) understand how quickly ALS is progressing. The most commonly used strength measurement is called handheld dynamometry (HHD). During HHD, the examiner holds a small gauge that the patient pushes against using different muscle groups.

Respiratory Function1

As respiratory (breathing) dysfunction remains the most common cause of death among people with ALS, assessing lung function is extremely important. A forced vital capacity (FVC) test is typically used for this. A FVC measures the maximum amount of air a patient can exhale from their lungs after taking the deepest possible breath.

The symptoms of ALS get worse over time. Therefore, it’s important to carefully monitor these symptoms and track your disease activity. This can help you and your healthcare provider(s) better understand how ALS is affecting your body and how quickly it’s progressing.

Ask your healthcare provider(s) about different measurements to track your ALS.

NEXT: ASSESSING FUNCTION

A medical reviewer who is an MD, PharmD, and/or PhD with Shionogi Inc. has reviewed and approved this content.Shionogi Inc. does not provide medical advice, diagnosis, or treatment. The health information contained herein is provided for general educational purposes only. Your healthcare professional is the best source of information regarding your health. Please consult your healthcare professional if you have any questions about your health or treatment.

References: 1. Amyotrophic lateral sclerosis (ALS). National Institute of Neurological Disorders and Stroke. Accessed May 18, 2026. https://www.ninds.nih.gov/health-information/disorders/amyotrophic-lateral-sclerosis-als 2. What is ALS? ALS Association website. https://www.als.org/understanding-als/what-is-als. Accessed May 18, 2026. 3. Mitchell JD, Borasio GD. Amyotrophic lateral sclerosis. Lancet. 2007;369:2031-2041. 4. Basic Facts about MND. Motor Neurone Disease Association website. https://www.mndassociation.org/about-mnd/what-is-mnd/basic-facts-about-mnd/. 5. Who gets ALS? The ALS Association. http://webco.alsa.org/site/PageServer/?pagename=CO_1_WhoGets.html. Last updated May 2019. Accessed May 18, 2026. 6. Beghi E, Mennini T, Bendotti C, et al. The heterogeneity of amyotrophic lateral sclerosis: a possible explanation of treatment failure. Curr Med Chem. 2007;14(30):3185-3200. 7. Cedarbaum JM, Stambler N, Malta E, et al. The ALSFRS-R: a revised ALS functional rating scale that incorporates assessments of respiratory function. J Neurol Sci. 1999;169(1-2):13-21. 8. Symptoms and diagnosis. ALS Association website. https://www.als.org/understanding-als/symptoms-diagnosis. Accessed May 18, 2026. 9. Rutkove SB. Clinical measures of disease progression in amyotrophic lateral sclerosis. Neurotherapeutics. 2015;12(2):384-393.