Yellow urine after taking medication may be a normal physiological phenomenon, or it may be caused by drug-induced liver damage or the patient’s own underlying diseases such as liver or gallbladder. 1. Physiological reasons: drinking too little water after taking medication causes an increase in reabsorption in the renal tubules, the urine is concentrated, resulting in symptoms such as yellowing of the urine and a decrease in the volume of urine. If drugs such as vitamin B2 and other metabolites show yellow, through the urine out of the body can also cause yellow urine. These are normal physiological phenomena, generally do not need to worry about, drink more water or stop the drug symptoms can be gradually relieved. 2. Drug-induced liver damage: adverse reactions caused by medication lead to liver damage, urine urobilinogen bilirubin rise may cause yellowing of urine. 3. Underlying lesions: viral hepatitis, alcoholic hepatitis, primary biliary cholangitis, cirrhosis, gallbladder cancer, pancreatic cancer, etc. may cause increased bilirubin and symptoms of yellow urine, which may also be accompanied by systemic symptoms, such as fever, yellowing of the skin, malaise, loss of appetite, and so on. In order to exclude the yellowing of urine caused by pathological factors, it is recommended to improve the urine examination in a timely manner to clarify the cause and then actively treat it to avoid delaying the condition.