Alzheimer's disease is a neurologic disorder in which death of brain cells cause memory loss and cognitive decline. A neurodegenerative type of dementia, the disease starts mild and gets progressively worse. Cause: It is thought to be caused by abnormal buildup of proteins in and around brain cells. Some proteins include amyloid and tau. 65% of people of 65 years and older are affected. Risk Factors: Age (above 65 years) Family History Certain gene ( the apolipoprotein E or APOE gene) Depression Hypertension Diabetes High Cholesterol High blood pressure Prior head injury Sleep disorders Low educational and occupational attainment. Symptoms include: Problems with language Disorientation Mood swings Loss of motivation Not managing self care Behavioural issues.