Alzheimer's disease is a progressive neurodegenerative disorder that primarily affects memory, thinking, and behavior. It is the most common cause of dementia, accounting for 60-80% of cases. Alzheimer's is characterized by the accumulation of amyloid-beta plaques and tau tangles in the brain, leading to the degeneration of neurons and synaptic loss. Early symptoms include mild memory loss and confusion, which gradually progress to severe cognitive decline, difficulty in communication, disorientation, and loss of independent functioning.The exact cause of Alzheimer's remains unclear, but risk factors include age, genetics, family history, and lifestyle. Current treatments focus on managing symptoms and slowing disease progression, though there is no cure. Research is ongoing to better understand the mechanisms behind Alzheimer's and develop more effective therapies. Early detection and intervention, combined with lifestyle changes such as mental stimulation, exercise, and a healthy diet, may help reduce the risk or delay the onset of the disease.