There are many possibilities for men to have yellow urine, which can be a physiological manifestation, a pathological manifestation, and a possible contamination of certain pigmented components of the diet. Need to do some necessary tests to clarify the cause. 1, in the physiological situation, the first urination in the early morning urine color is more yellow, is the night anti-diuretic hormone secretion and through the role of kidney concentration, is the normal physiological regulation, the purpose is to ensure that humans in the night of adequate sleep; when people drink less water, sweat more, vomiting diarrhea live in a high temperature environment bird color yellow is also a normal physiological phenomenon, due to the concentration of urine, inorganic salt components in the urine The concentration increases, it will lead to the color of the urine becomes yellow, this situation should pay attention to more water, while the physiological urine yellow color suggests that the kidney function is in good condition, because when the kidney function is damaged, the first to lose the concentration function. 2, consider that it is caused by eating pigmented ingredients, such as food, drugs, fruits and beverages containing pigmented ingredients, such as eating some foods that can easily cause yellow urine, like riboflavin, rifampin (anti-tuberculosis drugs), dragon fruit, etc., the metabolites of which will be discharged with the urine to darken the color of the urine, which will generally return to normal after a day or two after taking the drug. 3. Consider digestive system diseases, such as bile duct obstruction or hepatobiliary obstruction, as well as bile excretion disorders caused by acute and chronic hepatitis and liver cancer. The main component of bile is bilirubin, which is necessary for fat digestion in humans, but bile excretion is through the intestinal tract. In the case of the above diseases, bilirubin will flow back into the blood and be excreted through the kidneys, causing yellowing of urine. In short, there are many reasons for yellow urine, so we must pay attention to it and deal with it promptly after clarifying the cause to avoid delaying the condition.