Plasma phosphorylated tau-217 and amyloid-beta ratios now demonstrate 90% accuracy in detecting Alzheimer's pathology, matching expensive PET scans and lumbar punctures at a fraction of the cost. These assays can identify brain amyloid accumulation decades before cognitive symptoms emerge, potentially revolutionizing early intervention strategies. However, the transition from research tools to clinical practice introduces significant risks that demand careful consideration. Primary care physicians may lack specialized training to interpret complex biomarker profiles, leading to misdiagnosis or inappropriate treatment decisions. The technology's promise could exacerbate healthcare disparities if expensive follow-up testing or treatments remain inaccessible to underserved populations. False positives could trigger unnecessary anxiety and discrimination, while false negatives might delay critical interventions. The absence of standardized interpretation guidelines across healthcare systems creates additional variability in patient care. Most critically, effective Alzheimer's treatments remain limited, raising ethical questions about early detection without corresponding therapeutic options. These blood tests represent a paradigm shift toward precision neurology, but their clinical implementation requires robust training programs, equitable access protocols, and clearer treatment pathways to realize their potential benefit rather than inadvertently harm vulnerable patients.