Many people can’t drink because of alcohol allergy, medication, gastric ulcers and other reasons. 1. Alcohol allergy: part of the population due to the lack of acetaldehyde dehydrogenase in the body, after drinking alcohol, ethanol can not be metabolized into acetaldehyde immediately after the decomposition. In addition to causing damage to the liver, it will also lead to capillary dilation, showing flushing, rash, itching and other allergic symptoms, so you can’t drink. 2. Drugs: If you take cephalosporins, nitroimidazoles or other antibiotics for a long time, you usually can’t drink alcohol. Because the combination of drugs and alcohol will cause disulfiram-like reaction, resulting in dizziness, drowsiness, hallucinations, generalized flushing, headache, nausea, vomiting and other discomforts. 3. Gastrointestinal diseases: if the patient suffers from gastrointestinal diseases such as gastric ulcer, this time also can not drink alcohol, because alcohol will stimulate the mucous membrane of the stomach, causing stomach cramps, resulting in stomach pain, vomiting and other symptoms. There are more reasons for not being able to drink alcohol, such as cirrhosis of the liver, high blood pressure, heart disease, etc., are not able to drink alcohol. It is recommended that when this situation occurs, you should go to the hospital in time for a comprehensive examination to determine the cause of the disease, and under the guidance of the physician to treat the symptoms.