Many diseases are characterized by redness, fever and back pain, such as influenza, acute pyelonephritis, kidney stones, etc. It is recommended to go to the hospital for a targeted examination to determine the cause of the disease. Common causes are as follows: 1. Patients with influenza will have fever, runny nose, fatigue, back pain and other symptoms, nasopharyngeal symptoms are mild, mainly in the systemic symptoms. Antiviral drugs such as amantadine can be used under medical supervision. Symptomatic treatment, such as reducing fever and phlegm, can also be used to treat specific symptoms. 2. Acute pyelonephritis patients may have fever, urinary urgency, urinary frequency, urinary pain, lumbago and other symptoms, and physical examination may have pressure pain at the angle of the cribriform ridge or ureteral point and/or renal area percussion pain. It is recommended to seek timely medical treatment and anti-infection treatment. 3. Patients with kidney stones will have fever, flushing due to pain, and lumbar percussion pain at the onset of the disease. They should be examined promptly and the appropriate treatment plan should be chosen according to the size of the stones. There may be other causes, if there is discomfort, actively consult a doctor.