Alzheimer's disease is the most common type of dementia, according to the Alzheimer's Association. Dementia is a general term for loss of memory and other intellectual abilities. Alzheimer's disease usually develops slowly over time and causes problems with behavior, thinking and memory.
Symptoms of dementia vary, though they must include impairment of two of the following functions: memory, communication, language, reasoning, judgment, visual perception and focus, states the Alzheimer's Association. Alzheimer's symptoms specifically include difficulty remembering recently learned knowledge. Alzheimer's worsens progressively, beginning with mild memory loss and resulting in the inability to hold a conversation. Severe Alzheimer's patients also lose the ability to respond to their environment.