[12][13][14] There is no universal consensus on what the exact definition of middle age is, but usual characteristics include the beginning of rapid decline of fertility, graying of hair, and other physical changes.
Such changes are highly evident in the maturing relationships between growing or grown children and aging parents.
[19] Mortality rates can begin to increase, due mainly to health issues like heart problems, cancer, hypertension, and diabetes.
[20] Middle-aged urban adults who are experiencing frailty and poverty show an association with increased H2O2 induced oxidative DNA damage.
Middle age can be a time when people reexamine their lives by taking stock and evaluating their accomplishments.
[24] The perception that those in this stage of development of life undergo a so-called midlife crisis is a largely false one.