Inclusion Criteria:
1. Older than 18 years old
2. Acute liver injury within 3 months of onset and biochemical meeting one of the following criteria: ALT≥5 ULN; ALP≥2 ULN; ALT≥3 ULN and TBil≥2 ULN
3. The patients had a clear history of medication: the time from medication to onset, the time from drug withdrawal to onset, the time of the first laboratory test and the peak laboratory test, the reason for taking medication, the name of the drug, the dose of the drug, and the frequency. If the causative drug includes traditional Chinese medicine, the specific name of all the components or patent Chinese medicine in the prescription, a single drug or single component, or the main ingredient in the prescription causing liver injury should be provided
4. All the key data for RUCAM and RECAM can accurately be contained.
5. Follow-up outcomes confirmed that the cause of the acute liver injury was any of the following liver diseases: Drug-induced liver injury, acute viral hepatitis (including acute viral hepatitis A, acute viral hepatitis B or acute exacerbation of chronic hepatitis B, acute viral hepatitis E), alcoholic liver disease, autoimmune hepatitis, biliary calculi, biliary obstruction, hypoxic-ischemic hepatitis, congestive liver disease and other liver diseases
Exclusion Criteria:
1. The incubation period cannot be accurately calculated: the dates of starting medication, stopping medication, and onset of illness cannot be accurately described, resulting in the inability to calculate the incubation period
2. Can not be clear about the pathogenic drug: the pathogenic drug is only described as "traditional Chinese medicine, cold medicine, antipyretic medicine", but cannot be clear about what kind of medicine
3. Missing biochemical data, resulting in inability to assess the time of 50% decrease in liver biochemistry (ALT or ALP, TBIL) from the peak after drug withdrawal
4. The cause of the patient's acute liver injury could not be determined
5. Acetaminophen liver injury
6. Toxic liver disease, such as mushroom poisoning caused liver damage, chemical poisons (such as paint, etc.) liver damage
7. Previous liver transplantation and bone marrow transplantation
8. Pregnancy or lactation
