Lupus erythematosus is not contagious. Lupus erythematosus is an autoimmune system disease and is not contagious. However, lupus erythematosus is associated with genetic factors, and its onset is familial, so if more than one person in the family has the disease, it may be caused by genetic factors rather than by infection. The pathogenesis of lupus erythematosus is still unclear, mainly due to the destruction of immune tolerance, resulting in the production of a large number of autoantibodies in the body, which may be related to genetic factors, immune factors, drug factors, sex hormones and external physical and chemical stimuli, and therefore is not contagious. Patients with lupus erythematosus may have a variety of autoantibodies, mainly antinuclear antibodies. The clinical manifestations are complex and varied, with skin, kidney, liver, heart, joint and plasma membrane damage as the main manifestations. If the lesions are confined to the skin, it is called cutaneous lupus erythematosus; if the lesions involve the whole body, it is called systemic lupus erythematosus. Lupus erythematosus cannot be cured at present, and requires individualized and rational treatment according to the patient’s own condition, which can usually achieve long-term remission and control of the disease, thus improving the patient’s quality of life and prolonging the survival cycle. In addition to receiving medication, patients need to pay attention to sun protection and reduce UV exposure; patients who smoke need to quit smoking; they also need to keep warm, avoid straining and ensure a healthy diet to help control the disease.