C-reactive protein is not high but fever may be caused by viral infections, such as viral colds; it may also be a manifestation of malignant hematologic diseases such as lymphoma. C-reactive protein is one of the inflammatory indicators, and its elevation is common in bacterial infections, such as Streptococcus pneumoniae, Escherichia coli and other infections, and can also be seen in rheumatic immune diseases, such as systemic lupus erythematosus and so on. C-reactive protein is rarely elevated in viral infections, such as rhinovirus, adenovirus, respiratory syncytial virus and other viral colds, patients often have chills, high fever, but the C-reactive protein is often not elevated or mildly elevated, serum-like protein A can be significantly elevated. When lymphoma and other hematologic malignant diseases occur, some patients have fever, night sweats (sweating abnormally after going to sleep, and the sweating stops after waking up), weight loss, etc. This kind of patients mostly have low or moderate fever. It is recommended that the patient should consult a doctor in time, complete the relevant examination to clarify the specific cause of the disease, and then treat the cause of the disease.