Persistent fever is not necessarily rheumatic fever. Rheumatic fever is a rheumatic disease with a relatively low incidence at present. Although it has the word fever in its name, its symptoms are mainly arthritis and myocarditis, and it occurs in adolescents and children. In the acute phase of this disease, that is, after infection, fever may appear, usually moderate fever, and most of them disappear as the infection is controlled. Persistent fever needs to be differentiated from many diseases, such as common infections, such as respiratory tract infections, urinary tract infections or gastrointestinal tract infections, and the need to exclude specific types of infections such as tuberculosis or fungi. In addition, persistent fever also needs to exclude other rheumatic immune diseases, such as adult Steele’s disease, systemic lupus erythematosus, and rheumatoid arthritis, which can cause fever. There is also a type of persistent fever in the elderly that requires vigilance for malignant conditions such as malignant lymphoma, myeloma or lung cancer.