1. Epidemiological history History of blood transfusion, application of blood products or clear history of HCV exposure. The incubation period of acute hepatitis C after blood transfusion is 2 to 16 weeks (average 7 weeks), and the incubation period of sporadic acute hepatitis C has yet to be studied. 2, clinical manifestations generalized weakness, loss of appetite, nausea and pain in the right quadrant, a few with low-grade fever, mild hepatomegaly, some patients may develop splenomegaly, and a few patients may develop jaundice. Some patients have no obvious symptoms and show insidious infection. 3. Laboratory tests ALT is mostly mildly and moderately elevated, anti-HCV and HCV RNA are positive. HCV RNA often turns negative before ALT returns to normal, but there are cases where ALT returns to normal and HCV RNA remains positive. The diagnosis is made with 1+2+3 or 2+3 as described above.