In general, hospitalization is recommended for transaminases 400U/L. The normal reference range for transaminases is 0 to 40 U/L (the reference range may vary according to different measurement methods, depending on the reference value in the local hospital). Transaminases are mainly found in hepatocytes, cardiomyocytes, and skeletal muscle cells, and are commonly used clinically to reflect the severity of hepatocyte injury. When transaminases are elevated to 400 U/L, which is 10 times of the upper limit of normal, it suggests the presence of severe hepatocellular injury, which may indicate acute severe hepatitis, toxic hepatitis, cirrhosis and other diseases. Patients with transaminases 400U/L may also experience nausea, vomiting, fatigue, dizziness, loss of appetite, lethargy, jaundice and other symptoms, which can be life-threatening in severe cases. Transaminase 400U/L suggests timely hospitalization, under the guidance of specialists to clarify the cause of the disease, and targeted treatment.