Alzheimer's disease: Alzheimer's disease is the most common type of dementia. The way it changes the normal aging process is that it impairs the person's ability to recall conversations, events, and names. Other ways it changes the normal aging process include difficulty speaking, swallowing, confusion, depression, and walking. According to alz.org the survival rate can range form four to 20 years, which means that people with Alzheimer's disease have a shorter lifespan than those without.
Lewy Body