Alzheimer's disease (AD) is a progressive neurodegenerative disorder that affects the brain, causing memory loss, cognitive decline, and behavioral changes. It is the most common form of dementia, accounting for 60-80% of cases. This write-up aims to provide a detailed overview of Alzheimer's disease, including its causes, symptoms, diagnosis, progression, treatment, and ongoing research. I. Causes and Risk Factors: Age: Advancing age is the greatest risk factor for Alzheimer's disease. The majority of cases occur in individuals aged 65 and older. Genetics: Certain gene mutations, such as mutations in the APP, PSEN1, and PSEN2 genes, can increase the risk of developing early-onset familial Alzheimer's disease (FAD). Additionally, the presence of the APOE ε4 allele is a significant genetic risk factor for late-onset sporadic Alzheimer's disease. Lifestyle and Environmental Factors: Chronic conditions like cardiovascular disease, diabetes, obesity, hypertension, and a sedentary lifestyle may contribute to the development of Alzheimer's disease. Additionally, head injuries, low educational attainment, and social isolation have been associated with an increased risk. II. Pathology: Amyloid plaques: Abnormal accumulation of beta-amyloid protein forms plaques between nerve cells in the brain, disrupting cell communication and triggering inflammation. Neurofibrillary tangles: Tau protein abnormalities cause the formation of twisted tangles within neurons, leading to their malfunction and eventual death. Neurotransmitter and Synaptic Dysfunction: Alzheimer's disease disrupts the balance of neurotransmitters, impairing communication between brain cells and affecting memory and cognition. III. Symptoms and Stages: Mild Stage: Initially, individuals may experience mild memory lapses, difficulty finding words, and trouble with complex tasks. Moderate Stage: Memory loss intensifies, and cognitive decline becomes more evident. Confusion, mood swings, personality changes, and difficulty with language and motor skills emerge. Severe Stage: Individuals lose the ability to communicate, recognize loved ones, and perform basic tasks. They may require full-time care. IV. Diagnosis: Medical History and Evaluation: Physicians assess cognitive function, review medical history, and conduct interviews with the patient and family members. Cognitive and Memory Tests: Various tests evaluate memory, attention, problem-solving, and language skills. Brain Imaging: Magnetic resonance imaging (MRI) and positron emission tomography (PET) scans can help identify structural and functional changes in the brain. Biomarker Testing: Analysis of cerebrospinal fluid or blood samples may reveal abnormal levels of certain proteins associated with Alzheimer's disease. V. Treatment and Management: Medications: Cholinesterase inhibitors (e.g., donepezil, rivastigmine) and memantine are approved to manage symptoms and slow disease progression. Cognitive and Behavioral Interventions: Cognitive stimulation, memory training, and behavioral therapies can help manage symptoms and improve quality of life. Supportive Care: Creating a safe and structured environment, maintaining a healthy lifestyle, and providing emotional support to patients and caregivers are crucial components of care. VI. Current Research and Future Directions: Drug Development: Researchers are investigating potential disease-modifying therapies targeting amyloid plaques, tau protein, and inflammation. Biomarker Development: Efforts are underway to develop reliable biomarkers for early detection and monitoring of Alzheimer's disease. Lifestyle Interventions: Studies focus on the impact of exercise, diet, cognitive engagement, and social interactions on reducing the risk and progression of Alzheimer's disease.