It is possible that back pain in patients with hepatitis B is not directly related to hepatitis B. Because the main organ damaged by the hepatitis B virus is the liver, if there is significant liver inflammation, or even cirrhosis or liver cancer, the site of pain is usually in the hypochondrium, or in the right upper abdomen, and does not directly involve the lower back, so other causes of back pain should be considered. If it is related to hepatitis B, it is possible that the hepatitis B virus is causing the associated kidney damage. In addition to liver damage, the hepatitis B virus can also cause damage to other organs, like kidney damage is one that can be seen occasionally. In this case, you should check the kidney function of the patient, do kidney ultrasound to determine the size of the kidney, see if there is urine protein and blood in the urine, and determine if it is hepatitis B virus-related nephropathy.