Arm pain with high fever is not caused by fever, but by the cause of the fever, such as local inflammation, connective tissue disease or neoplastic disease. 1. Local inflammation: it may be caused by a bacterial infection in the arm area, for example, localized purulent infections often lead to arm pain accompanied by high fever. 2. Connective tissue diseases: for example, systemic lupus erythematosus, rheumatoid arthritis, etc., in the acute stage of the disease, often cause fever, joint swelling and pain and other symptoms. 3. Tumor diseases: most commonly seen in malignant tumors occurring in the arm area of lymph node metastasis or bone metastasis, the emergence of tumor absorption fever. If you have arm pain when you have high fever, you should go to the hospital in time to find out the cause and then target treatment, so as to avoid delaying the treatment.