Aging is the process of the degeneration of cells and tissues, which results in many physical and mental changes. It is a complex biological process, which causes deterioration of health with the passage of time. When a person ages, the body loses its capacity to regrow cells and tissues in order to compensate the losses incurred by the body due to cell death. In other words, the rate of cell degeneration surpasses the rate of cell regeneration in aging.