Amyotrophic lateral sclerosis (ALS) is not something you can “get” on purpose or “catch” from another person; it develops inside the body due to a mix of genetic and other risk factors that are still not fully understood.

Quick Scoop: What is ALS?

ALS (amyotrophic lateral sclerosis) is a progressive neurological disease that damages motor neurons, the nerve cells that control voluntary muscles such as those used for walking, speaking, and breathing. Over time this leads to muscle weakness, difficulty speaking and swallowing, and eventually serious breathing problems.

How do people develop ALS?

You do not “get ALS” from touching, kissing, sharing food, sex, or being near someone who has it; it is not contagious in any way. In most people, the exact cause is unknown, but experts think it usually involves several factors working together:

  • Genetic factors
    • Around 5–10% of ALS cases are “familial,” meaning a gene variant runs in the family and increases risk.
* In these families, a child of an affected parent often has about a 50% chance of inheriting the gene change, but even inheriting a risk gene does not guarantee you will develop ALS.
  • Sporadic (non‑familial) ALS
    • The vast majority of people with ALS have no clear family history of the disease.
* Researchers suspect that some people are genetically more vulnerable and then, over a lifetime, certain environmental or biological triggers (for example, aging, oxidative stress, or toxins) may contribute, but there is no single proven “cause” you can point to for most people.
  • Known risk factors (not direct causes)
    • Age: ALS is most often diagnosed between about 60 and the mid‑80s.
* Sex: Before about age 65, it is slightly more common in men than women, but this difference fades at older ages.

* Family history: Having a close relative with ALS increases your personal risk, but overall the chance of any one family member developing ALS is still low.

Can you “catch” or intentionally cause ALS?

  • ALS is not contagious like a cold, flu, HIV, or COVID‑19; you cannot get it through air, saliva, blood, or ordinary contact.
  • There is no known action, behavior, or single exposure that reliably “causes” ALS in a specific person, and you cannot deliberately give yourself ALS.
  • Even in families with a known gene mutation, some people who inherit the gene never develop symptoms, which shows how complex and incomplete our understanding of cause still is.

If you are asking because you are worried about symptoms (for example, ongoing muscle twitching, weakness, or trouble speaking or swallowing), the only useful next step is to see a doctor—ideally a neurologist—for an exam and any needed tests such as EMG or imaging. Early evaluation cannot prevent ALS if it is present, but it can help confirm or rule out the diagnosis and start supportive treatment as soon as possible.

TL;DR: You cannot “get ALS” from other people, and there is no simple, controllable way to cause it; most cases arise from a complicated mix of genes, aging, and other factors that science is still working to fully explain.

Information gathered from public forums or data available on the internet and portrayed here.