Every year, World Health Day is celebrated on 7 April to mark the anniversary of the founding of the World Health Organization (WHO) in 1948. Each year a theme is selected for World Health Day that highlights a priority area of concern for WHO.

The theme for 2012 is Ageing and health. Using the slogan “Good health adds life to years“, campaign activities and materials will focus on how good health throughout life can help older men and women lead full and productive lives and be a resource for their families and communities.

Over the past century life expectancy has increased dramatically and the world will soon have more older people than children.

Populations are ageing everywhere, but less-developed countries are witnessing the fastest change. This social transformation represents both challenges and opportunities. In particular, countries may only have a single generation to prepare their health and social systems for an ageing world.

Key facts

  • The number of people today aged 60 and over has doubled since 1980.
  • The number of people aged 80 years will almost quadruple to 395 million between now and 2050.
  • Within the next five years, the number of adults aged 65 and over will outnumber children under the age of 5.
  • By 2050, these older adults will outnumber all children under the age of 14.
  • The majority of older people live in low- or middle-income countries. By, 2050, this number will have increased to 80%.

In the 21st century, health is determined by and contributes to broad social trends. Economies are globalizing, more and more people live and work in cities, family patterns are changing and technology is evolving rapidly. One of the biggest social transformations is population ageing. Soon, the world will have more older people than children and more people of very old age than ever before.

1. The world will have more people who live to see their 80s or 90s than ever before

The number of people aged 80 years or older, for example, will have almost quadrupled to 395 million between 2000 and 2050. There is no historical precedent for a majority of middle-aged and older adults having living parents, as is already the case today. More children will know their grandparents and even their great-grandparents, especially their great-grandmothers. On average, women live six to eight years longer than men.

2. The past century has seen remarkable improvements in life expectancy

In 1910, the life expectancy for a Chilean female was 33 years; today, a mere century later, it is 82 years. This represents a remarkable gain of almost 50 years of life in one century, and is largely due to improvements in public health.

3. Soon, the world will have more older people than children

Within the next five years, for the first time in human history, the number of adults aged 65 and over will outnumber children under the age of 5. By 2050, these older adults will outnumber children under the age of 14.

4. The world population is rapidly ageing

Between 2000 and 2050, the proportion of the world’s population over 60 years will double from about 11% to 22%. The absolute number of people aged 60 years and over is expected to increase from 605 million to 2 billion over the same period.

5. Low- and middle-income countries will experience the most rapid and dramatic demographic change

For example, it took more than 100 years for the share of France’s population aged 65 or older to double from 7 to 14%. In contrast, it will take countries like Brazil and China less than 25 years to reach the same growth.