Alzheimer’s disease (AD) is the most common form of loss of memory. AD is a degenerative disease of the brain and the sixth leading cause of death in the elderly. Alzheimer’sdisease (AD) is one of the most common problems for old peoples, genetic factors play a major role in determining a person’s risk to develop AD. AD includes two thirds of all dementia. AD is a progressive and an age dependent disease that leads to the irreversible loss of nerve cell, particularly in the cortex and hippo-campus of the brain. The clinical factors present progressive impairment in memory, judgment, decision making, orientation to physical surroundings, and language. Although the exact mechanism, prevention and treatment of this disease are under research following few facts are worth sharing. Cardiovascular disease patients and individuals with history of head injury show higher AD risk than normal. A family history of AD in the first-degree relatives leads to a positiv