Hepatitis B can be detected by blood donation. Before donating blood, the four tests of hepatitis B, C, syphilis and AIDS as well as the liver function test should be done. If there are problems with liver function or if you have hepatitis B, C, AIDS or syphilis, which are diseases that can be transmitted from blood, then you cannot donate blood, so you need to do all these tests before donating blood. Patients with hepatitis B can be tested positive for hepatitis B surface antigen through pre-donation screening, but this indicator can only tell that they have hepatitis B. However, the extent of the disease and whether further treatment is needed requires further examination, including liver function, hepatitis B five items, hepatitis B virus DNA, and liver imaging, such as liver ultrasound. The treatment plan will be given after consultation.