Lack of adequate fluid in the body and a crucial factor in the health of older people.

A disturbance of brain function that causes confusion and changes in alertness, attention, thinking and reasoning, memory, emotions, sleeping patterns and coordination. These symptoms may start suddenly, may be due to some type of medical problem, and may get worse or better multiple times.

Loss of one's bearings, loss of sense of familiarity with one's surroundings, or loss of one's bearings with respect to time, place and person.

Instructions written by a doctor telling other healthcare providers not to try to restart a patient's heart, using cardiopulmonary resuscitation (CPR) or other related treatments, if his/her heart stops beating. Usually, DNR orders are written after a discussion between a doctor and the patient and/or family members.

A legal document that specifies one or more individuals (called a health care proxy) designated to make medical decisions for a person if that person is incapacitated.