Aging is a gradual, ongoing process of natural change in the body that begins in early adulthood. In early middle age, many of the body's functions begin to gradually decline.
People do not become old or senile at any particular age. Traditionally, old age is considered to begin at age 65. But the reason for this is historical, not biological. Many years ago, age 65 was chosen as the retirement age in Germany, the first nation to create a retirement program. In 1965 in the United States, age 65 was defined as the age of eligibility for Medicare coverage. This age is close to the actual retirement age of most people in economically developed societies.
The question of when a person becomes elderly can be answered in different ways.
Most healthy and active people do not need the help of a geriatrician (a doctor who specializes in medical care for the elderly) until they are 70, 75, or even 80 years old. However, some people need to see a geriatrician at a younger chronological age because of their medical conditions.
People often ask whether what they experience as they age is normal or not. Although all people age differently to some extent, some changes may be the result of internal processes, that is, aging itself. Thus, these changes, although undesirable, are considered normal and are sometimes referred to as "true aging." These changes occur in everyone who lives long enough, and this universality is part of the definition of true aging. These changes are expected and usually unavoidable. For example, as we age, the lens of the eye becomes thicker, stiffer, and less able to focus on near objects such as printed matter (this disorder is called presbyopia). This change occurs in almost all older adults. Presbyopia is thus considered part of normal aging. The terms "normal aging" and "senility" are also used to describe these changes.
It is not always clear exactly what processes constitute normal aging. The changes that occur as normal aging progresses predispose people to develop certain disorders. However, sometimes people can take steps to compensate for these changes. For example, older people are more likely to lose teeth. But regular visits to the dentist, eating less candy, and regular brushing and rinsing can reduce the likelihood of tooth loss. Thus, tooth loss can be avoided even though it is a common feature of aging.
In addition, the decline in body function that is part of aging sometimes resembles the decline in body function that occurs as a result of a disorder. For example, in old age, a mild decline in thinking ability is almost universal and is considered normal aging. This decline includes increased difficulty learning new things such as languages, unsteady attention span and increased forgetfulness. In contrast, the decline in thinking abilities seen in dementia is much more severe. For example, people in the process of normal aging may put things in the wrong places or forget details of events, while people with dementia forget events completely. People with dementia also have difficulty performing normal daily activities (such as driving, cooking, and managing finances) as well as understanding surrounding circumstances, for example, they may not know what year it is or where they are. Dementia is thus considered a disorder, although it is frequent later in life. Certain types of dementia, such as Alzheimer's disease, differ from normal aging in other characteristics as well. For example, brain tissue (obtained during autopsy) from people with Alzheimer's disease differs in appearance from brain tissue from older people who do not have the disease. Therefore, the difference between normal aging and dementia is obvious.
Sometimes the difference between the decline in bodily functions that is part of aging and the decline in bodily functions that occurs as a result of a disorder seems tentative. For example, older people have a greater increase in blood sugar levels after consuming carbohydrates than younger people. This rise is considered normal aging. However, if it exceeds a certain level, a person is diagnosed with diabetes. In this case, the only difference is the degree.
Healthy aging refers to delaying or reducing the undesirable effects of aging. The goals of healthy aging are to maintain physical and mental health, prevent impairment, and remain active and independent. For most people, maintaining good health in general requires more and more effort as they age. It may help to develop certain healthy habits, such as:
The earlier a person develops these habits, the better. However, it is never too late to start. That way, people can have some control over the processes that happen to them as they age.
Some data suggest that healthy aging is on the rise in the United States:
The average life expectancy of Americans has increased significantly over the last hundred years. It was expected that a boy born in 1900 could only live 46 years and a girl 48 years. In 2019, life expectancy in the U.S. for the entire population was 79 years. While much of this increase can be attributed to a significant decrease in infant mortality, life expectancy at any age after age 40 has also increased significantly. For example, a 65-year-old man can now live to about age 83, and a 65-year-old woman can now live to about age 86. Overall, women live about 5 years longer than men. This difference in life expectancy has changed little despite changes in women's lifestyles in the late 20th and early 21st centuries, including smoking and exposure to more stress.
Although average life expectancy has increased, maximum life expectancy, the oldest age a person can live to, has changed little since written evidence has been available. Even with the best set of genes and the healthiest lifestyle, the likelihood of living to age 120 is negligible. Madame Jeanne Kalman has the longest documented life expectancy: 122 years (1875-1997)
Several factors influence life expectancy: