Dementia is a progressive and largely irreversible clinical syndrome that is characterized by a widespread impairment of mental function.
Although many people with dementia retain positive personality traits and personal attributes, as their condition progresses they can experience some or all of the following: memory loss, language impairment, disorientation, changes in personality, difficulties with activities of daily living, self neglect, psychiatric symptoms (e.g., apathy, depression, psychosis) and out of character behavior (e.g., aggression, sleep disturbance, disinhibited sexual behavior — although the latter is not typically the presenting feature of dementia).

Dementia is associated with complex needs and, especially in the later stages, high levels of dependency and morbidity. These care needs often challenge the skills and capacity of carers and services. As the condition progresses, people with dementia can present carers and social care staff with complex problems, including aggressive behavior, restlessness and wandering, eating problems, incontinence, delusions and hallucinations, and mobility difficulties that can lead to falls and fractures. The impact of dementia on an individual may be compounded by personal circumstances, such as changes in financial status and accommodation, or bereavement.

See reference for more information.

Dementia. Supporting people with dementia and their careers in health and social care. National institute for Health and Clinical Excellence (NICE) Guideline November 2006. Internet. Available at https://www.nice.org.uk/guidance/cg42 Accesed on June 21, 2016.

Dementia is not a specific disease. It's an overall term that describes a wide range of symptoms associated with a decline in memory or other thinking skills severe enough to reduce a person's ability to perform everyday activities.
Alzheimer's disease accounts for 60 to 80 percent of cases. Vascular dementia, which occurs after a stroke, is the second most common dementia type. But there are many other conditions that can cause symptoms of dementia, including some that are reversible, such as thyroid problems and vitamin deficiencies.

Dementia is often incorrectly referred to as "senility" or "senile dementia," which reflects the formerly widespread but incorrect belief that serious mental decline is a normal part of aging.

See reference for more information.

Adapted from Alzheimer's Association. Internet. Accessed on October 3, 2017.