Age is the most significant risk factor for Alzheimer's disease. The majority of individuals with Alzheimer's are diagnosed at age 65 or older, with fewer than 10% of cases occurring before this age. The risk of developing Alzheimer's increases with advancing age, approximately one in 13 individuals aged 65 to 84 and one in three individuals aged 85 and older are affected. Additional key risk factors include family history, lifestyle choices, existing medical conditions, and genetic markers (presence of the apolipoprotein E APOE gene).