Getting up in the morning to urinate yellow can be caused by many reasons, such as physiological reasons, pathological reasons and drug factors. 1. Physiological reasons: physiological yellow urine is usually due to drinking too little water, resulting in urine concentration, which leads to yellow urine. It can be relieved by drinking more water. 2. Pathological causes: yellow urine can also be caused by infectious diseases of the urinary system, such as: urethritis, cystitis, pyelonephritis, such diseases can lead to urinary tract infections, which will also appear in the phenomenon of yellow urine. In addition, liver and gallbladder diseases can cause bilirubin metabolism abnormalities, so that the urine bilirubin and urobilinogen elevated, will also cause yellow urine. 3. drug factors: some drugs can also affect the color of urine, making the urine yellow, such as taking large doses of vitamin B2, may also appear yellow urine. Physiological causes of yellowing of the urine is recommended to drink more water; pathological causes of yellowing of the urine need to consult a doctor in a timely manner, the treatment of the original disease; medication factors caused by yellowing of the urine in the discontinuation of medication will be relieved on their own.