Systemic lupus erythematosus (SLE) is a complex, chronic autoimmune disease characterized by multisystem involvement and a wide spectrum of clinical manifestations. Central to its pathogenesis is a breakdown in immune tolerance, resulting in the generation of a broad range of autoantibodies and immune complex deposition that leads to tissue damage. The development of SLE is multifactorial, involving a combination of genetic susceptibility, environmental exposures (such as infections and ultraviolet radiation), and hormonal factors. These elements contribute to immune dysregulation, particularly through the activation of type I interferon pathways and impaired clearance of apoptotic cells, which further perpetuate inflammation and autoimmunity. The clinical presentation of SLE is highly variable, affecting the skin, joints, kidneys, central nervous system, and other organs. Diagnosis is often challenging and relies on a combination of clinical and immunological criteria, as outlined in the 2019 EULAR/ACR classification system. Effective management of SLE necessitates a personalized, multidisciplinary approach that incorporates the use of antimalarial, corticosteroids, immunosuppressive agents, and biologic therapies, tailored to the severity and specific organ involvement. Despite significant advancements in treatment, patients remain at risk for serious complications including cardiovascular disease, opportunistic infections, and malignancies. Long-term prognosis is improved through regular monitoring, patient education, and coordinated care aimed at reducing flares and preserving organ function.