A positive EBV IgA antibody indicates previous or ongoing EBV infection, indicating a higher likelihood of nasopharyngeal tumor, but further examination of IgG and IgM antibodies in the body is needed to determine this. IgA antibody is one of the chlamydial antigen antibodies of EBV, which is valuable in the diagnosis of nasopharyngeal cancer and is an important indicator for clinical use in screening high-risk groups. A positive IgA antibody is also seen in infectious mononucleosis, and a positive IgG and IgM chlamydial antigen antibodies, combined with clinical symptoms, can basically confirm the diagnosis. Patients with nasopharyngeal carcinoma often show symptoms such as tinnitus, hearing loss, nasal congestion, facial numbness and enlarged lymph nodes in the neck. Common symptoms of infectious mononucleosis include irregular fever, swollen lymph nodes, sore throat, headache, lack of appetite and other symptoms. The main treatment modalities include surgery, chemotherapy, radiotherapy, etc. If diagnosed, treatment should be actively carried out to prevent metastasis of cancer cells so as to better control the disease.