Alzheimer's disease is a neurological condition that gradually impairs memory, self-awareness, and cognitive capacities. It is the most frequent cause of dementia and a major factor in senior patient deaths. It is generally acknowledged that the condition is multifactorial, resulting from intricate interactions between age, genetics, and environment, even though the exact cause is unknown. Early start of the condition can be caused by mutations in the APP, PSEN1, and PSEN2 genes, which can result in an autosomal dominant inheritance pattern. The most prevalent kind is late-onset, in which the APOE ε4 allele is the primary genetic risk factor. TREM2, CLU, and PICALM are among the other genes that raise the risk. The primary molecular pathways are the build-up of beta-amyloid proteins, which result in amyloid plaques, and the hyperphosphorylation of tau, which forms neurofibrillary tangles and causes neuronal death by necrosis, autophagy, and apoptosis. Acetylcholine, glutamate, GABA, and noradrenaline neurotransmission are all impacted, which has an effect on cognition and memory.In conclusion, Alzheimer's disease is a complicated neurological disorder that causes progressive cognitive impairment due to both hereditary and molecular components.