ALS is rare. In the United States, roughly 10 out of every 100,000 people are living with the disease at any given time, which translates to about 33,000 Americans as of 2022. Each year, approximately 1.44 new cases are diagnosed per 100,000 people. While those numbers are small compared to conditions like diabetes or heart disease, ALS carries an outsized impact because of how quickly it progresses and how few effective treatments exist.
How Many People Have ALS in the U.S.
The CDC’s National ALS Registry tracks cases across the country and estimates prevalence at 10.1 per 100,000 people as of 2025. That number has been gradually climbing, partly because the population is aging and partly because detection methods have improved. The Registry projects that by 2030, the total number of Americans living with ALS will rise by more than 10%, surpassing 36,000 cases.
To put the rarity in perspective: for every one person diagnosed with ALS, there are roughly 70 people diagnosed with multiple sclerosis and over 100 diagnosed with Parkinson’s disease. ALS is classified as an orphan disease, meaning it affects a small enough share of the population that it qualifies for special drug development incentives.
ALS Rates Around the World
ALS exists everywhere, but rates vary significantly by region. A large systematic review published in Neurology found that point prevalence ranged from 1.57 per 100,000 in Iran to 11.80 per 100,000 in the United States. Annual incidence was similarly uneven, spanning from 0.26 per 100,000 in Ecuador to 23.46 per 100,000 in Japan. These differences likely reflect a mix of genetics, environmental exposures, diagnostic access, and how thoroughly each country tracks the disease. Countries with older populations and well-resourced health systems tend to report higher rates, in part because more cases get identified.
Who Gets ALS
ALS is not evenly distributed across the population. Several factors influence who is more likely to develop it.
Age: Risk rises steadily with age up to about 75. The disease is most common between ages 60 and the mid-80s, though younger adults can develop it too. The average age at diagnosis is in the early to mid-60s.
Sex: Men are diagnosed more often than women, at a ratio of about 1.6 to 1. In concrete terms, prevalence in men runs around 6.4 per 100,000 compared to 4.0 per 100,000 in women. This gap narrows somewhat in older age groups.
Race and ethnicity: White Americans have the highest incidence, followed by Black Americans and then Asian Americans. Non-Hispanic individuals are diagnosed at higher rates than Hispanic individuals. These patterns have held across the largest studies comparing racial and ethnic groups, though researchers are still working to understand how much of the gap comes from biology versus differences in healthcare access and reporting.
Your Lifetime Risk
Because ALS is a disease you can develop at any point in life, the cumulative lifetime risk is higher than the snapshot prevalence might suggest. A population-based study tracking ALS over 24 years in Ireland calculated that roughly 1 in 347 men and 1 in 436 women will develop the disease at some point in their lives. Those figures translate to a lifetime risk of about 0.3% for men and 0.2% for women. It’s still a small probability, but it’s meaningfully larger than the “one in 100,000” figure that gets cited without context.
Inherited vs. Sporadic Cases
About 90% to 95% of ALS cases are sporadic, meaning they occur in people with no family history of the disease. The remaining 5% to 10% are familial, where a genetic mutation passed down through the family plays a direct role. If you have a first-degree relative with ALS, your risk is higher than the general population’s, but most people who develop ALS have no known genetic link.
Even in sporadic cases, genetics likely plays some role alongside environmental triggers. Researchers have identified dozens of gene variants that slightly increase susceptibility. The picture that’s emerging is one where ALS sits on a spectrum: at one end, a single powerful gene mutation causes the disease outright, and at the other, a combination of minor genetic risk factors and environmental exposures tips the balance.
What Happens After Diagnosis
Part of what makes ALS so significant despite its rarity is the prognosis. The average life expectancy after diagnosis is three to five years. About 30% of people live five years or longer, and 10% to 20% survive at least a decade. Survival varies widely depending on which parts of the body are affected first, how quickly symptoms progress, the person’s age at diagnosis, and how early treatment and supportive care begin.
The combination of low prevalence and poor survival creates a pattern where the number of people living with ALS at any one time stays relatively small, even though new cases are constantly being diagnosed. That steady turnover is one reason the prevalence figure stays near 10 per 100,000 despite ongoing diagnoses year after year.