Lou Gehrig’s disease, formally known as ALS (amyotrophic lateral sclerosis), is rare. Roughly 1.4 to 1.8 people per 100,000 are diagnosed each year in the United States, and the CDC projects about 34,700 Americans will be living with the disease in 2026. To put that in perspective, your lifetime risk of developing ALS is roughly 1 in 300 to 1 in 400.
How Many People Get ALS Each Year
The worldwide pooled incidence of ALS is about 1.75 new cases per 100,000 people per year. In the U.S., the age-adjusted rate is approximately 1.79 per 100,000. That translates to around 5,000 to 6,000 new American diagnoses annually. These numbers make ALS one of the more common motor neuron diseases but still firmly in the “rare disease” category, which the federal government defines as any condition affecting fewer than 200,000 people nationally at a given time.
Rates are not uniform around the world. Populations of European descent in Europe, North America, and New Zealand show fairly consistent incidence, pooling at about 1.81 per 100,000. East Asia (China and Japan) sees roughly half that rate, around 0.83 per 100,000, and South Asia is lower still at about 0.73. Whether these differences reflect genetics, environmental factors, or gaps in diagnosis and reporting remains an open question.
Who Is Most Likely To Be Diagnosed
ALS is not equally distributed across age, sex, or race. About 80% of people diagnosed are between 50 and 79 years old, with the average age at diagnosis sitting right around 65. Incidence climbs sharply after age 45 and peaks in the 70 to 79 age group, where the rate reaches nearly 11 per 100,000, roughly six times higher than the overall population rate.
Men develop ALS more often than women. Around 55% of cases are male, giving men roughly 1.25 times the risk. This gap is consistent across most studies and countries, though it tends to narrow somewhat in older age groups.
Race and ethnicity also play a role. In the U.S., white Americans are diagnosed at nearly twice the rate of Black Americans (1.48 vs. 0.89 per 100,000 after adjusting for age) and about twice the rate of Asian Americans (0.78 per 100,000). Hispanic Americans also have a significantly lower rate than non-Hispanic Americans, at 0.84 versus 1.36 per 100,000. Researchers are still working to understand how much of this variation is biological versus related to differences in healthcare access and diagnostic patterns.
Military Veterans Face Higher Risk
One group stands out in the research: military veterans. Studies consistently show that men who served in the military have roughly 1.5 to 2 times the ALS mortality rate of men who never served. One large Texas study found veterans had 2.28 times the odds of dying from ALS compared to non-veterans. The same elevated risk has not been clearly established for women veterans. The exact cause is unclear, but researchers have explored links to physical trauma, chemical exposures, and intense exertion during service. The Department of Veterans Affairs recognizes ALS as a service-connected disease for all veterans with 90 or more days of active duty.
Sporadic vs. Inherited ALS
About 90% of ALS cases are sporadic, meaning they appear without any family history or identifiable genetic cause. The remaining 10% are familial, where a known gene mutation is passed down. If you have a first-degree relative with ALS, your risk is higher than the general population, but the vast majority of people with a family member who had the disease will never develop it themselves. Several dozen genes have been linked to familial ALS so far, with the most common mutations affecting a gene called C9orf72.
Survival and Prognosis
ALS is a progressive disease, and the typical survival window is relatively short. Population-based studies put median survival at 20 to 36 months from symptom onset, though there is meaningful variation. Between 10% and 20% of people with ALS survive beyond five years, and 5% to 10% live longer than 10 years. Stephen Hawking, who lived more than 50 years after his diagnosis, was an extraordinary outlier.
Several factors influence how quickly the disease progresses. Younger age at diagnosis, limb-onset symptoms (as opposed to symptoms starting in the muscles controlling speech and swallowing), and longer time between first symptoms and diagnosis all tend to correlate with slower progression. But individual trajectories vary widely, and no current test can reliably predict how fast any one person’s disease will advance.
ALS Is Expected To Become More Common
ALS prevalence is projected to rise meaningfully over the next two decades. In the U.S., the prevalence rate is expected to climb from about 9.1 per 100,000 in 2018 to 11.2 per 100,000 by 2040. Globally, the median projected increase is about 25% between 2024 and 2040. Two forces are driving this: aging populations (since ALS primarily strikes people over 60, and that demographic is growing fast in most countries) and modestly improving survival times as supportive care advances. Japan, with its rapidly aging population, is projected to see prevalence reach 14.18 per 100,000 by 2040, representing over 16,000 people living with the disease.
None of this means ALS will stop being rare. Even with these increases, it will remain an uncommon diagnosis. But the absolute number of people living with the disease at any given time will grow, putting increasing pressure on healthcare systems and caregiving resources in the years ahead.