30 cases. According to the requirements of inquiring medical papers, in order to ensure the accuracy of data in medical papers, the number of cases is required to be more than 30 ~ 50, and 30 ~ 50 cases can represent the characteristics of diseases to a great extent. A case is an example of a disease. To be concise, the patient's name, gender, age, occupation, place of origin, work unit or address, chief complaint, current medical history, past history, various positive and negative signs, diagnosis or impression, treatment and treatment opinions, etc. , are recorded in the medical record, and signed by the doctor.