From aches and pains to worrying about our pensions, getting older is something many of us find a bit daunting.
But there's good news - research suggests that we get happier as we progress through our sixties.
Britons who were asked about their wellbeing were found to be significantly happier at 69 than they had been when they answered the survey in their early 60s.
This was despite most of them developing chronic diseases such as arthritis, diabetes and high blood pressure, the scientists said.
The findings came from a study of more than 3,000 men and women who have been tracked since their births in 1946, known as the UK's National Survey for Health and Development (NSHD). The survey has been used to research a range of health and social issues.
To assess happiness as we age, researchers asked the participants to rate their levels of 14 aspects of mental wellbeing, including how cheerful, confident, optimistic, useful and relaxed they felt.
They were surveyed when they were aged 60 to 64, and again when they were 69. The scientists wrote that when the men and women answered the questions when they were older, "there was an improvement in all 14 items that make up the wellbeing scale compared to their responses in their early 60s".
The reasons for this rise in happiness were not explained, although the researchers, from the Medical Research Council (MRC) and University College London, now intend to look into what life experiences could be contributing to it.
Dr Mai Stafford, programme leader at the MRC's Lifelong Health and Ageing unit, said:
"What we've found is that, on average, levels of wellbeing increased during people's sixties. We found that one in five experienced a substantial increase in wellbeing in later life, although we also found a smaller group who experienced a substantial decline.
"The benefit of using a cohort study like NSHD is that we can look at how individuals change over time. We hope this will allow us to pinpoint which common experiences may be linked to an improvement in wellbeing in later life."
Their findings support research earlier this month from the Office for National Statistics, which found those aged 65 to 79 were the most content. In that report, 45 to 59-year-olds were the most miserable.
Happiness levels also dropped off after 80, but not to the same lows as those reported by the middle aged.
The ONS study suggested that the reason for increased happiness in our sixties and seventies could be that "those who are retired may have more time to spend on activities which promote their wellbeing".
A study by the University of Warwick last year also found that our wellbeing levels hit a low in our 40s, but then keep rising until 85.
The NSHD is the longest-running study following a group of people from birth in the UK. It has allowed scientists to look for patterns and links between our genes, environment, lifestyle and our health.