Alzheimer's disease (AD) is a silent invisible monster that affects our beloved seniors. It is regarded as the most common cause of dementia. It involves the loss of intellectual and social abilities in a way that is severe enough to interfere with daily functioning. Memory loss along with a gradual decline of cognitive functions, including intellectual and thinking abilities, and changes in personality and behaviour are the main symptoms of the disease. In the highly advanced stages of Alzheimer's disease, a person becomes helpless and dependent on others for everyday aspect. This book is a complete review of the etiology and treatment of such a disease.