Here's where to draw the line between early and late onset AD. Alzheimer's disease (AD) is a condition characterized by degeneration and death of brain cells that leads to a steady decline in memory and mental functions. There are primarily two types of AD: The Alzheimer's Association describes the 10 warning symptoms and signs for Alzheimer's disease. To know more you may visit http://www.alz.org/alzheimers_disease_10_signs_of_alzheimers.asp.
In this less common type of AD, symptoms appear before age 65. The symptoms, however, may get worse quickly. Early onset AD may run in families.