While Alzheimer's disease is the most common form of dementia, there are also other common types such as vascular dementia, Lewy body dementia and Frontotemporal dementia. There are also rarer types of dementia that are caused by other diseases and conditions.

Stage 3: Mild dementia Problems with memory and thinking may become more noticeable to friends and family and also begin to affect daily life. Symptoms of mild dementia due to Alzheimer's disease include: having difficulty remembering newly learned information.

While dementia is a general term, Alzheimer's disease is a specific brain disease. It is marked by symptoms of dementia that gradually get worse over time. Alzheimer's disease first affects the part of the brain associated with learning, so early symptoms often include changes in memory, thinking and reasoning skills.

Agitation (physical or verbal aggression, general emotional distress, restlessness, pacing, shredding paper or tissues and/or yelling). Delusions (firmly held belief in things that are not real). Hallucinations (seeing, hearing or feeling things that are not there).