An estimated 222,801 people were living with ALS worldwide as of 2015, the most recent global projection available. That number is expected to rise to roughly 376,674 by 2040, a 69% increase driven largely by aging populations in developing nations. ALS remains a rare disease, but its impact is significant: it progressively destroys the nerve cells that control voluntary movement, and median survival after diagnosis is just 2 to 4 years.
Global Cases and Prevalence Rates
ALS prevalence varies dramatically depending on where you look. In the United States, point prevalence reaches as high as 11.80 per 100,000 people, one of the highest rates recorded anywhere. Italy reports similarly elevated numbers at 10.80 per 100,000. At the other end of the spectrum, Iran has a reported prevalence of just 1.57 per 100,000.
These gaps don’t necessarily mean ALS strikes certain populations more often in a biological sense. Countries with older populations, better-funded healthcare systems, and more neurologists tend to detect and record more cases. In regions where access to specialists is limited, many people with ALS likely go undiagnosed or are misdiagnosed with another condition. The projected increase to 376,674 cases by 2040 is itself considered an underestimate, since healthcare access and diagnostic capabilities continue to improve in lower-income countries.
How Rates Differ by Region
Europe has some of the most robust ALS tracking data. Across 29 prevalence studies, rates ranged from 3.44 per 100,000 in Malta to 10.80 per 100,000 in Italy. New diagnoses per year ranged from about 1.11 per 100,000 in Serbia to 5.55 per 100,000 in Denmark. Scotland, Austria, and Denmark consistently reported the highest incidence rates on the continent, while Serbia, Russia, and Cyprus reported the lowest.
In Asia, annual incidence ranged from 0.42 per 100,000 in Iran to 2.20 per 100,000 in Japan. Two isolated Japanese communities, the Kii Peninsula and Oshima, recorded unusually high rates of 6.42 and 23.46 per 100,000 respectively. These clusters have long fascinated researchers and may reflect a combination of genetic and environmental factors unique to those populations.
North American incidence ranged from 0.50 to 3.29 per 100,000, with both ends of that range coming from Canadian studies. South America had limited data, but prevalence estimates fell between 4.90 per 100,000 in Colombia and 8.86 per 100,000 in Argentina.
Who Gets ALS
ALS is more common in men than women, with an overall male-to-female ratio of about 1.25 to 1. That gap is more pronounced in sporadic cases (those without a family history), where the ratio rises to 1.29 to 1. In familial ALS, the ratio is essentially equal at 1.05 to 1, suggesting that the inherited forms of the disease affect men and women at similar rates while something about the non-inherited form favors men.
The disease is rare before age 40. It increases sharply with age after that point, with peak incidence occurring in people aged 70 to 79. The average age when symptoms first appear is 58 to 63 for sporadic ALS and somewhat younger, 40 to 60, for familial cases. About 90% to 95% of all ALS cases are sporadic, meaning they occur in people with no family history of the disease. The remaining 5% to 10% are familial, linked to inherited genetic mutations.
Diagnosis Often Takes Nearly a Year
One reason ALS numbers are hard to pin down is the long road to diagnosis. The median time from first symptom to confirmed diagnosis is 11.5 months. That timeline breaks down into several stages: people typically wait about four months before seeing a doctor, then another three months pass before ALS is suspected, and roughly one more month before the diagnosis is confirmed. Some patients fall well outside these medians. A quarter of people in one large study waited 20 months or longer for a confirmed diagnosis.
This delay matters because ALS progresses during the entire diagnostic window. Early symptoms like muscle twitching, weakness in a hand or foot, or slurred speech can mimic many other conditions, and no single blood test or scan can confirm ALS. Diagnosis relies on ruling out other possibilities and observing the pattern of nerve cell loss over time.
Survival and Long-Term Outlook
Median survival after diagnosis is 2 to 4 years, with one large cohort study placing it at 2.2 years. That number reflects the reality that ALS progresses rapidly for most people, eventually affecting the muscles used for breathing.
A small but real subset of patients, roughly 5% to 15%, survive significantly longer. In one study, long-term survivors had a median survival of 13.4 years. What distinguishes these individuals isn’t fully understood, though younger age at onset and slower initial progression appear to play a role. The wide gap between the 1.9-year median for typical cases and the 13.4-year median for long survivors underscores how variable this disease can be, even though its overall trajectory is predictable.
Why the Numbers Are Rising
The projected 69% increase in global ALS cases between 2015 and 2040 is not because the disease itself is becoming more common per person. The primary driver is demographics. The world’s population is aging, and since ALS risk climbs steeply after age 40, more older people means more cases. This effect is especially pronounced in developing nations, where life expectancy has risen rapidly over recent decades. As those populations age into the peak risk window for ALS, case counts will follow. Improved diagnostic access in these same regions will compound the increase, bringing cases to light that previously went unrecorded.