Causes of prolonged fever include pathogenic bacterial infections, immune diseases, tumors and so on.
1. Pathogenic bacterial infections: Streptococcus pneumoniae, S. typhi, inflammatory mediators and other pyrogens can cause febrile symptoms, and if the pyrogens are not eliminated, the fever can remain unresolved for a long time.
2. Immune diseases: autoimmune diseases such as systemic lupus erythematosus and desiccation syndrome can cause persistent or intermittent fever due to inflammatory reaction or necrotic material absorption.
3. Tumor: serious infection exists in cancer patients, and the lesion of tumor causes obstruction of cavity, and the concurrent infection of patients is often difficult to be relieved, resulting in the existence of persistent fever. For example, obstructive pneumonia caused by lung cancer, cancerous intestinal obstruction caused by gastrointestinal tumor.
If the fever does not return for a long time, there may be other pathologic factors. It is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or therapy under the guidance of the doctor.