Sudden fever without symptoms may be triggered by lymphoma, but the disease is mostly characterized by enlarged lymph nodes. Blood and bone marrow tests, ultrasound, CT and other tests are recommended to rule out the presence of lymphoma. Sudden fever without symptoms can be caused by a variety of reasons, such as influenza virus infection, hyperthyroidism, drug fever, connective tissue disease and so on. Although lymphoma can also present with fever, it is mainly manifested by painless progressive lymph node enlargement or localized lumps, and can be accompanied by systemic symptoms such as night sweating, itching, and loss of weight. Therefore, it is not possible to determine whether the patient has lymphoma by sudden onset of fever. It is recommended to check the blood routine, blood sedimentation, superficial lymph node ultrasound, PET/CT, etc., and if necessary, collect bone marrow smear, lymph node puncture or section for pathological examination to assist in the diagnosis and to clarify the cause. Sudden onset of fever, even without symptoms, should be consulted in the hospital to clarify the cause and provide symptomatic treatment.