Dementia is the progressive decline in cognitive function due to damage or disease in the brain beyond what might be expected from normal aging. Particularly affected areas may be memory, attention, language and problem solving, although particularly in the later stages of the condition, affected persons may be disoriented in time, not knowing what day, week, month or year it is, not knowing where they are not knowing who they are. Symptoms of dementia can be classified as either reversible or irreversible depending upon the etiology of the disease. Less than 10% of all dementias are reversible. Dementia is a non-specific term that encompasses many disease processes, just as fever is attributable to many etiologies. Early symptoms of dementia often consist in changes in personality, or in behavior. Often dementia can be first evident during an episode of delirium. There is a higher prevalence of eventually developing dementia in individuals who experience an acute episode of confusion while hospitalized. Dementia can affect language, comprehension, motor skills, short-term memory, ability to identify commonly used items, reaction time, personality traits, and executive functioning. Even without signs of general intellectual decline, delusions are common in dementia (15-56% incidence rate in Alzheimer's type, and 27-60% incidence rate in multi-infarct dementia). Often these delusions take the form of monothematic delusions, like mirrored self-misidentification. Elderly people can also react with dementia-like symptoms to surgery, infections, sleep deprivation, irregular food intake, dehydration, loneliness, change in domicile or personal crises. This is called delirium, and many if not most dementia patients also have a delirium on top of the physiologial dementia, adding to the symptoms. The delirium can go away or greatly improve when treated with tender care, improved food and sleeping habits, but this does not affect the alterations in the brain. Affected persons may also show signs of psychosis or depression. It is important to be able to differentiate between delirium and dementia. Proper differential diagnosis between the types of dementia will require, at the least, referral to a specialist, e.g. a geriatric internist, geriatric psychiatrist or neurologist. However, there are some brief 5-15 minute tests that have good reliability and can be used in the office or other setting to evaluate cognitive status. Except for the treatable types listed above, there is no cure to this illness, although scientists are progressing in making a type of medication that will slow down the process. Disclaimer - The information presented here should not be interpreted as medical advice. If you or someone you know suffers from Dementia, please consult your physician for the latest treatment options. Permission is granted to reprint this article as long as no changes are made, and the entire resource box is included.