Dementia is a syndrome, not a specific diagnosis. There are more than 70 recognized disorders that cause dementia and the ultimate responsibility of determining the precise cause of dementia lies with a multidisciplinary team or dementia clinic. Mild dementia, however, is often missed unless mental status is formally assessed. Transient global amnesia (TGA) is a rare, but dramatic entity with a benign prognosis. TGA is characterized by abrupt, temporary inability to form new memories (anterograde amnesia) and variable impairment of recent and remote memory. TGA spares nonmemory functions, such as language and visuospatial skills. The diagnostic evaluation of dementia is best done in the outpatient setting. Common complications, such as pneumonia and urinary tract infection, are considered in demented patients with a precipitous decline in cognition. Infectious precautions are required when evaluating patients with rapidly progressive dementia.