ALS is rare. About 1.4 new cases are diagnosed per 100,000 people in the United States each year, and roughly 33,000 Americans are living with the disease at any given time. To put that in perspective, your lifetime risk of developing ALS is about 1 in 347 if you’re a man and 1 in 436 if you’re a woman. It’s uncommon enough that most doctors will see only a handful of cases in their careers, yet common enough that nearly everyone has heard of it.
U.S. Cases and Prevalence
The CDC’s National ALS Registry estimates that close to 33,000 people in the U.S. were living with ALS as of 2022, with that number projected to rise more than 10% to over 36,000 by 2030. The current prevalence rate sits at about 10.1 per 100,000 adults. That steady climb isn’t because ALS itself is becoming more common in any given age group. It reflects an aging population: more people are reaching the ages where ALS typically strikes, and modest improvements in care are helping some patients survive slightly longer.
Who Gets ALS
ALS is not equally distributed across every demographic group. Men develop ALS about 1.5 times more often than women, though that gap narrows at older ages. The disease most commonly appears between ages 60 and 79, with peak onset in the 60s. The median age at diagnosis is around 62 for non-Hispanic white Americans.
Race and ethnicity play a significant role in ALS rates. White Americans are diagnosed at roughly 1.8 per 100,000 per year, compared to 0.8 for Black Americans, 0.8 for Asian Americans, and 0.6 for Hispanic Americans. Black and Hispanic patients also tend to be diagnosed younger, with a median age of 58 compared to 62 for non-Hispanic white patients. Whether these differences reflect true biological variation, differences in access to specialist care and diagnosis, or some combination remains an open question.
Sporadic vs. Familial ALS
About 90% to 95% of ALS cases are sporadic, meaning they appear in people with no family history of the disease. The remaining 5% to 10% are familial, where the disease runs in the family and is linked to inherited genetic mutations. A large meta-analysis pooling 165 studies found the overall proportion of familial cases was about 8%. In practical terms, the vast majority of people who develop ALS have no close relatives with the condition.
Military Veterans Face Higher Risk
Military service is one of the few consistently identified risk factors for ALS beyond age and sex. A meta-analysis of nine studies found that military personnel had about 29% higher odds of developing ALS compared to civilians. The risk appears particularly elevated for certain groups: Gulf War veterans had roughly double the expected rate, and some studies found World War II veterans were at significantly higher risk as well.
The reasons aren’t fully understood, but exposure to pesticides (including Agent Orange), certain industrial chemicals, exhaust fumes, heavy metals, and head trauma during service all appear to contribute. Because of this established link, ALS is treated as a service-connected disease by the U.S. Department of Veterans Affairs regardless of when or where a veteran served.
Global Rates and Geographic Patterns
Worldwide, ALS incidence ranges from about 0.3 to 3.6 new cases per 100,000 people per year. Rates tend to be highest in Europe and North America and lower in Asia, Africa, and South America, though underdiagnosis in regions with less access to neurological care likely accounts for some of that gap.
A few geographic clusters have puzzled researchers for decades. In the 1950s, the island of Guam, the Kii Peninsula in Japan, and parts of southwestern New Guinea all had ALS rates far above the global average. The Guam cluster has since declined dramatically, suggesting environmental rather than purely genetic factors were at work.
Cases Are Expected to Rise
Because ALS primarily affects older adults, the global aging trend means more cases are coming. Projections estimate a median 25% increase in ALS prevalence across multiple countries between 2024 and 2040. In some regions of Europe, the prevalence could reach nearly 16 per 100,000 by 2040. If survival continues to improve even modestly with newer therapies, the number of people living with ALS at any point in time will climb further still. The disease will remain rare in absolute terms, but less rare than it has been historically.