Middle age is a relative concept. Although the term literally means a mid-point between birth and death, most Americans consider it to fall in the years between forty and sixty.

During these years, health problems or a parent’s death remind us that life is finite.

Balancing the needs of children and aging parents, while assessing career goals, creates a convergence of life events that is accompanied by a re-evaluation of the life lived, with adjustments of expectations for the future.

People experience becoming middle aged at different points, depending on life experiences. The early onset of chronic illness can evoke these feelings in the thirties.

Likewise, good health and an active lifestyle may postpone the perception of middle age until the sixties or even seventies. For those starting families in their forties, the feeling of middle age may occur later in life. During the 1960s, the youth culture motto was “Never trust anyone over thirty.” As those who chanted that slogan now enter middle age, they are reassessing their lives and redefining aging.

American culture is intensely youth oriented, thus middle age is rarely greeted with enthusiasm. The baby boomer population has embraced the anti-aging industry with gusto. Researchers are exploring options for delaying the aging process. Plastic surgery, hair transplants, physical fitness, New Age cures and vitamin and hormonal supplements may be sought to offset the effects of aging. Many of these remedies are expensive and only available to the more affluent.

Middle age is marked by health-related changes that will continue into old age, although there is no clear dividing line between the two stages. Physical signs can occur simultaneously with the development of chronic health problems. Loss of flexibility and stamina are common. Hormones change, signaling the onset of menopause for women.

Male menopause—andropause—refers to the lethargy and depression that may accompany middle age.

Midlife crises can occur and may involve upheavals in relationships and careers. Some will recognize that the endless possibilities of youth are no longer available. Aware that life is half over, they may rebel against day-to-day routines. A teacher supporting a family may realize he or she will not become a famous screenwriter as he or she once dreamed. Others may suddenly regret a choice of partner and yearn for carefree youth.

Men may marry younger women, cynically called “trophy wives,” and start a new family Women may pursue education or a career that was postponed due to child rearing.

Although many find midlife to be a stressful time of transition and re-evaluation, others find empowerment. New freedoms and opportunities become available as responsibilities to children and aging parents are fulfilled. Careers and finances may be more stable. Some will emerge from middle age feeling satisfied with their choices and excited about their life ahead.