According to Shaufta Feroz, M.D. “…an individual is living three different age levels at the same time.” Those age levels are one’s chronological age, based on the calendar, biological age, based on our physical condition, and psychological age, based on how old we feel. Feroz says the psychological age dominates, although all three are interdependent. A healthy lifestyle and good attitude can lead to holistic aging rather than degenerative aging. Examples of holistic aging include having a pleasant temperament, enjoying natural sleep, and taking few medications. Signs of degenerative aging include suffering from acute and chronic diseases, feeling irritable, living in the past, and being generally unhappy with life.