Alzheimer's disease is the most common suffering from dementia disease and is a gradual, permanent, incurable neurodegenerative illness. It usually begins after the age of 60 and lasts for 8 to 12 years. Cognitive degradation, loss of functional independence, behavioral changes, and an increase in the need for care are all symptoms of this disease's slow and steady progression. The burden of neocortical neurofibrillary tangles was found to have a pathological correlation of cognitive impairment in clinicopathological studies. The most prevalent symptom of Alzheimer's disease is a persistent impairment in episodic memory.