Dementia usually occurs in older age. It is rare in people under age 60. The risk of dementia increases as a person gets older.
Most types of dementia are nonreversible (degenerative). Nonreversible means the changes in the brain that are causing the dementia cannot be stopped or turned back. Alzheimer disease is the most common type of dementia.
Another common type of dementia is vascular dementia. It is caused by many small strokes.
Lewy body disease is a common cause of dementia in the elderly. People with this condition have abnormal protein structures in certain areas of the brain.
The following medical conditions can also lead to dementia:
Use of certain medicines, including cimetidine and some cholesterol drugs
Dementia symptoms include difficulty with many areas of mental function, including:
Emotional behavior or personality
Thinking and judgment (cognitive skills)
Dementia usually first appears as forgetfulness.
Mild cognitive impairment (MCI) is the stage between normal forgetfulness due to aging and the development of dementia. People with MCI have mild problems with thinking and memory that do not interfere with daily activities. They often know about their forgetfulness. Not everyone with MCI develops dementia.
Symptoms of MCI include:
Difficulty doing more than one task at a time
Difficulty solving problems or making decisions
Forgetting recent events or conversations
Taking longer to do more difficult mental activities
Early symptoms of dementia can include:
Difficulty with tasks that take some thought, but that used to come easily, such as balancing a checkbook, playing games (such as bridge), and learning new information or routines
Getting lost on familiar routes
Language problems, such as trouble with the names of familiar objects
Losing interest in things previously enjoyed, flat mood
Personality changes and loss of social skills, which can lead to inappropriate behaviors
As dementia becomes worse, symptoms are more obvious and interfere with the ability to take care of oneself. Symptoms may include:
Change in sleep patterns, often waking up at night
Difficulty with basic tasks, such as preparing meals, choosing proper clothing, or driving
Forgetting details about current events
Forgetting events in one's own life history, losing self-awareness
People with mild cognitive impairment do not always develop dementia. When dementia does occur, it usually gets worse over time. Dementia often decreases quality of life and lifespan. Families will likely need to plan for their loved one's future care.
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Galvin JE, Sadowsky CH; NINCDS-ADRDA. Practical guidelines for the recognition and diagnosis of dementia. J Am Board Fam Med. 2012;25:367-382. PMID: 22570400 www.ncbi.nlm.nih.gov/pubmed/22570400.
Knopman DS. Alzheimer disease and other dementias. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 402.
Joseph V. Campellone, MD, Division of Neurology, Cooper University Hospital, Camden, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.