In some countries, current demographic trends show that lowered fertility rates, increased life expectancy and lower mortality rates have contributed to the ageing of the population, and increase in chronic health conditions has implications for health-care systems and spending, informal care systems and research. Given the gap between male and female life expectancy, the number of widows and older single women has increased considerably, often leading to their social isolation and other social challenges. Societies have much to gain from the knowledge and life experience of older women. On the other hand, the current generation of young people is the largest in history. Adolescent girls and young women have particular needs which will require increasing attention.