Urine is the excretory waste produced by the kidney to filter blood, which contains the component of urinary pigment. Urine pigment is derived from bilirubin, which is the metabolite of hemoglobin. The concentration of urinary pigment determines the color of urine. If you drink less water at ordinary times or do not drink at night when you get up in the morning, the urine is concentrated, and the color of urine is darker at this time, Therefore, the color of urine is often darker after morning urine or insufficient water intake. Some drugs, food, and disease status will affect the color of urine. For example, after taking rifampicin, the color of urine will turn red, while after taking vitamin B2, the urine will turn yellow. After taking chloroquine, brown urine will appear. In addition, if there is some old blood in the urine, dark black urine will appear.
