Re-emergence of fever two days after the flu has subsided may be related to factors such as incomplete killing of the flu virus, co-infections of the lungs, and self-inflicted diseases.
1. Failure to kill the influenza virus completely is a common cause of illness. If targeted antiviral treatment is not given when the fever subsides at the initial stage, the influenza virus will still multiply in the body even though the fever symptoms are under control, thus causing the fever to return.
2. Combined lung infection is also a common cause. If the virus is not completely killed, or combined with bacterial infection, it can lead to pneumonia, resulting in recurrent fever.
3. Self-illness, if there are leukemia, rheumatoid arthritis, systemic lupus erythematosus, malignant tumors and other underlying diseases, can also cause recurrent fever.
Therefore, it is recommended to consult a doctor in a timely manner, to clarify the cause of the disease after examination, and at the same time to follow the doctor’s instructions for treatment.