Geriatrics, or geriatric medicine, is a specialty that focuses on health care of elderly people. It aims to promote health by preventing and treating diseases and disabilities in older adults. There is no set age at which patients may be under the care of a geriatrician, or geriatric physician, a physician who specializes in the care of elderly people. Rather, this decision is determined by the individual patient's needs, and the availability of a specialist. It is important to note the difference between geriatrics, the care of aged people, and gerontology, which is the study of the aging process itself. The term geriatrics comes from the Greek γέρων geron meaning 'old man', and ιατρός iatros meaning 'healer'. However, geriatrics is sometimes called medical gerontology. Geriatrics, or geriatric medicine, is a specialty that focuses on health care of elderly people. It aims to promote health by preventing and treating diseases and disabilities in older adults. There is no set age at which patients may be under the care of a geriatrician, or geriatric physician, a physician who specializes in the care of elderly people. Rather, this decision is determined by the individual patient's needs, and the availability of a specialist. It is important to note the difference between geriatrics, the care of aged people, and gerontology, which is the study of the aging process itself. The term geriatrics comes from the Greek γέρων geron meaning 'old man', and ιατρός iatros meaning 'healer'. However, geriatrics is sometimes called medical gerontology. Geriatrics differs from standard adult medicine because it focuses on the unique needs of the elderly person. The aged body is different physiologically from the younger adult body, and during old age, the decline of various organ systems becomes manifest. Previous health issues and lifestyle choices produce a different constellation of diseases and symptoms in different people. The appearance of symptoms depends on the remaining healthy reserves in the organs. Smokers, for example, consume their respiratory system reserve early and rapidly. Geriatricians distinguish between diseases and the effects of normal aging. For example, renal impairment may be a part of aging, but renal failure and urinary incontinence are not. Geriatricians aim to treat diseases that are present and achieve healthy aging. Geriatricians focus on achieving the patient's highest priorities in the context of multiple chronic conditions, and on preserving function. The decline in physiological reserve in organs makes the elderly develop some kinds of diseases and have more complications from mild problems (such as dehydration from a mild gastroenteritis). Multiple problems may compound: A mild fever in elderly persons may cause confusion, which may lead to a fall and to a fracture of the neck of the femur ('broken hip'). Elderly people require specific attention to medications. Elderly people particularly are subjected to polypharmacy (taking multiple medications). Some elderly people have multiple medical disorders; some have self-prescribed many herbal medications and over-the-counter drugs. This polypharmacy may increase the risk of drug interactions or adverse drug reactions. In one study, it was found that prescription and nonprescription medications were commonly used together among older adults, with nearly 1 in 25 individuals potentially at risk for a major drug-drug interaction. Drugs metabolites are excreted mostly by the kidneys or the liver, which may be impaired in the elderly, necessitating medication adjustment. The presentation of disease in elderly persons may be vague and non-specific, or it may include delirium or falls. (Pneumonia, for example, may present with low-grade fever and confusion, rather than the high fever and cough seen in younger people.) Some elderly people may find it hard to describe their symptoms in words, especially if the disease is causing confusion, or if they have cognitive impairment. Delirium in the elderly may be caused by a minor problem such as constipation or by something as serious and life-threatening as a heart attack. Many of these problems are treatable, if the root cause can be discovered. The so-called geriatric giants are the major categories of impairment that appear in elderly people, especially as they begin to fail. These include immobility, instability, incontinence and impaired intellect/memory. Impaired vision and hearing loss are common chronic problems among older people. Hearing problems can lead to social isolation, depression, and dependence as the person can no longer talk to other people, receive information over the telephone, or engage in simple transactions, such as talking to a person at a bank or store. Vision problems lead to falls from tripping over unseen objects, medicine being taken incorrectly because the written instructions could not be read, and finances being mismanaged. Functional abilities, independence and quality of life issues are of great concern to geriatricians and their patients. Elderly people generally want to live independently as long as possible, which requires them to be able to engage in self-care and other activities of daily living. A geriatrician may be able to provide information about elder care options, and refers people to home care services, skilled nursing facilities, assisted living facilities, and hospice as appropriate.