Health care, or healthcare, refers to the treatment and management of illness, and the preservation of health through services offered by the medical, dental, pharmaceutical, clinical laboratory sciences nursing, and allied health professions. Health care embraces all the goods and services designed to promote health, including preventive, curative and palliative interventions, whether directed to individuals or to populations. Physical fitness refers to good body health, and is the result of regular exercise, proper diet and nutrition, and proper rest for physical recovery. A strong indicator of the health of localized population is their height or weight, which generally increases with improved nutrition and health care. Personal health depends partially on the social structure of one's life. The maintenance of strong social relationships is linked to good health conditions, longevity, productivity, and a positive attitude.