Dementia is a condition that affects memory and thinking enough to interfere with normal daily activities. About 1 out of every 10 Americans older than 65 years of age has some degree of dementia. Poor memory alone is not dementia, and some declines in short-term memory are normal as people age. Several diseases can cause dementia, but the two most common are Alzheimer disease and cerebrovascular dementia. In Alzheimer disease, the buildup of abnormal proteins damages brain cells. In cerebrovascular dementia, low blood flow to the brain damages brain cells. There is no cure for dementia. However, drugs called cholinesterase inhibitors can modestly slow the worsening of disease. Also, some nondrug management strategies might be useful in delaying the need for nursing home care. Doctors should consider a diagnosis of dementia if a patient reports problems with memory and thinking. However, it is unclear whether it makes sense for primary care doctors to screen for dementia in patients who do not report these problems. Screening is looking for a specific condition in people who do not report symptoms of that condition.