In clinical practice, about 40-75% of patients with acute HCV infection do not have any uncomfortable symptoms, and only patients with elevated serum ALT are discovered accidentally when seeking treatment for other diseases or during physical examinations, or they are discovered due to a history of blood transfusion or injection, and anti-HCV positivity and elevated ALT are detected by vigilant doctors during medical consultations. The clinical presentation is usually mild and is referred to as subclinical. Half of the patients recover on their own. However, re-exposure to HCV results in reinfection. HCV infection is associated with peripheral discomfort, malaise, loss of appetite, occasional nausea, and in a few patients, pain in the liver area, jaundice, and other symptoms typical of acute hepatitis. However, in general, few cases present with jaundice, and if they do, the jaundice is relatively mild. ALT may be normal or only mildly elevated, and some patients have persistently elevated ALT. The ALT may be normal or only mildly elevated, but some patients have persistent elevation of ALT, which is generally classified into 3 types: 1. Recurrent type: This type is typical of HCV infection. 2, persistent abnormal type: This type of ALT is persistently elevated, but the value of ALT is only about 1-2 times higher than normal. The liver biopsy also shows chronic hepatitis changes with varying severity of lesions. Persistent and recurrent types are seen in both the acute and chronic phases of infection. 3.Healthy carrier type: This type has normal ALT and liver biopsy may be normal or show varying degrees of chronic hepatitis changes. Since viraemia may still exist in healthy carriers, a normal ALT does not negate the possibility of chronic hepatitis C. Some cases are often overlapping infections with hepatitis B virus and have more severe symptoms than hepatitis C infection alone. The severity of infection is often associated with multiple blood transfusions, high transfusion volumes, and active hepatitis virus replication in the imported blood. The recipient is at risk for acute hepatic necrosis or subacute hepatitis with a poor prognosis and high mortality rate.