Dementia is a chronic or persistent disorder of the mental processes caused by brain disease or injury and marked by memory disorders, personality changes, and impaired reasoning. It is known as ‘Smriti Nasha’ in Ayurveda. Dementia is a general term for a decline in mental ability severe enough to interfere with daily life. Alzheimer's is the most common type of dementia. Common symptoms of dementia are memory loss, impaired judgment, difficulties with abstract thinking, faulty reasoning, inappropriate behaviour, loss of communication skills, disorientation to time and place. Dementia is usually caused by degeneration in the cerebral cortex, head injury, brain tumours, infections (such as meningitis, HIV / AIDS, or syphilis, hormone disorders metabolic disorders, hypoxia, nutritional deficiencies, drug abuse, or chronic alcoholism. Ayurveda is found to be more effective to cure dementia by the use of herbs, Panchakarma therapies and other modalities like, sirodhara, nasya etc.