An aging population is a shift in a country’s age structure where older individuals make up a proportionally larger share of the total population. This happens when people live longer and have fewer children, gradually tilting the balance so that the median age rises and the percentage of older residents grows. Between 1974 and 2024, the worldwide share of people aged 65 and older nearly doubled, climbing from 5.5% to 10.3%. That trend is accelerating, and it’s reshaping economies, healthcare systems, and social safety nets in every region of the world.
How an Aging Population Is Measured
Demographers typically use age 65 as the threshold for “older,” since that’s roughly when rates of chronic illness and mortality begin to rise noticeably. The UN sometimes uses 60 as the cutoff, but 65 is the more common standard in economic and policy discussions. Two key metrics capture the scale of the shift: the share of the total population that is 65 or older, and the old-age dependency ratio, which counts the number of people aged 65 and up for every 100 people of working age (20 to 64).
A country where more than 14% of the population is 65 or older is generally classified as an “aged” society. When that figure crosses 20%, some researchers call it a “super-aged” society. Japan, Italy, and several other nations have already crossed that line.
What’s Driving the Shift
Two forces are pushing populations older simultaneously: falling birth rates and rising life expectancy.
Global fertility has dropped dramatically. In 1950, the average woman had about 4.8 children over her lifetime. By 2021, that number had fallen to 2.2, barely above the 2.1 replacement level needed to keep a population stable without immigration. In dozens of countries, fertility is now well below replacement. Fewer babies entering the population each year means the average age creeps upward even if nothing else changes.
At the same time, people are living longer. Global healthy life expectancy rose by nearly four years between 2000 and 2021 alone, reaching about 62 years. Total life expectancy is higher still. Improvements in sanitation, nutrition, medicine, and public health mean more people survive into their 70s, 80s, and beyond. The number of people aged 80 and older is projected to more than triple over the next 50 years.
Where Aging Is Most Advanced
Europe and East Asia are the epicenters. As of early 2025, Italy leads the EU with a median age of 49.1 years and nearly a quarter of its population (24.7%) aged 65 or older. Portugal (24.3%) and Bulgaria (24.0%) are close behind. Ireland, with a median age of 39.6, is the youngest EU country, but even there the trend is heading in the same direction.
Japan is often cited as the world’s most extreme case, with roughly 29% of its population over 65. South Korea, Germany, and Finland are also well into “super-aged” territory. But aging is not limited to wealthy nations. China, Brazil, Thailand, and many middle-income countries are aging rapidly, sometimes faster than their wealthier counterparts did, which gives them less time to build the economic and social infrastructure needed to support older populations.
Economic Pressures
The most immediate economic consequence is a shrinking workforce relative to the number of retirees. When the old-age dependency ratio rises, fewer working-age people are generating the tax revenue and economic output that funds pensions, healthcare, and social services. OECD countries have seen prolonged increases in life expectancy that most analysts project to continue, meaning the number of pensioners will keep climbing.
This creates pressure on pension systems in two ways. Retirees draw benefits for more years than the systems were originally designed to support, and there are proportionally fewer workers paying into those systems. The math eventually stops working without some combination of higher contributions, reduced benefits, or later retirement ages. Many countries are already raising their official retirement ages in response.
Labor shortages in sectors like healthcare, construction, and manufacturing become more common as the working-age population shrinks. Some countries try to offset this through immigration, automation, or policies that encourage higher workforce participation among women and older adults. None of these fully solve the problem on their own.
Healthcare Strain
Older populations need more medical care, and the relationship is not linear. In Italy, where the data has been tracked closely, 86% of adults over 65 had at least one chronic condition as of 2014, and nearly 57% had two or more. People with multiple chronic conditions are hospitalized more often, take more medications, and need more diagnostic tests. Italian outpatient healthcare utilization, including prescriptions, lab tests, and doctor visits, jumped roughly 26 to 27% over a ten-year period. Those services already consumed about 20% of the country’s total public healthcare budget.
The pattern is similar across aging societies. More people living longer with conditions like heart disease, diabetes, arthritis, and dementia means healthcare systems need more staff, more facilities, and more funding at the exact moment when the tax base supporting those systems is proportionally smaller. Without significant preventive efforts, experts warn that the financial sustainability of public healthcare systems will come under serious strain, with downstream effects on labor supply and GDP.
What the Next Few Decades Look Like
The UN projects that the global share of people aged 65 and older will double again by 2074, reaching roughly 20.7%. By 2050, the World Health Organization estimates that around 16 to 22% of the global population will be 60 or older, depending on which age threshold is used. These are not speculative scenarios. The people who will be 65 in 2050 are already in their late 30s and 40s today. The demographic momentum is locked in.
Countries that are aging fastest face the most urgent timelines. South Korea’s working-age population is already contracting. China’s is expected to shrink substantially over the coming decades, a shift with global economic implications given the country’s role in manufacturing and trade.
How Countries Are Responding
Governments are experimenting with a range of strategies, though no single approach has proven sufficient on its own. Raising the retirement age is the most common fiscal response, extending the period during which people contribute to pension systems and shortening the period during which they draw from them. Most European countries have already raised or are in the process of raising their retirement ages, some linking them automatically to life expectancy projections.
Long-term care financing is another major area of reform. Germany, Japan, and South Korea have introduced mandatory long-term care insurance systems, spreading the cost of eldercare across the entire working population rather than leaving it to individual families or general tax revenue. These programs fund home care, assisted living, and nursing home stays for people who can no longer manage daily activities independently.
On the healthcare delivery side, some regions are restructuring how care is provided to older adults. In Torbay, England, for example, multidisciplinary teams from health and social care have been integrated in community hospitals, so older patients with complex needs don’t bounce between disconnected services. The goal is to keep people healthier and more independent for longer, which is both better for quality of life and cheaper than repeated hospitalizations.
Pronatalist policies, from child tax credits to subsidized childcare, have been tried in countries from France to Hungary to Singapore with mixed results. Fertility rates are influenced by deep cultural and economic factors, and most interventions have produced only modest and temporary bumps in birth rates. Immigration remains the fastest way to supplement a shrinking workforce, though it comes with its own political and social complexities.