Brown urine may be caused by physiological factors and pathological factors such as injuries, urinary tract infections, urinary stones, urinary tract tumors and other factors. 1. Physiological factors: women in the physiological cycle, menstrual blood discharge, into the urine, it will lead to the urine color becomes brown, belong to physiological factors, after the menstrual cycle will return to normal. 2. Pathological factors: (1) Injury: such as large burns, excessive compression injuries, may make the red blood cells are destroyed, it will lead to the urine contains more red blood cells, so that the color of urine becomes brown. (2) urinary system infection: for example, cystitis, when the infection is more serious, resulting in localized damage to the bladder, will make the presence of pus secretion, red blood cells and other substances in the urine, which will make the urine brown, accompanied by urinary frequency, urgency, urinary pain and other symptoms. (3) Urinary stones: For example, bladder stones, after causing damage to the bladder, brown urine will appear during urination, which may also be accompanied by urinary pain, difficulty in urination, frequent urination and other symptoms. (4) Urinary system tumor: For example, bladder tumor, the tissue necrosis on the surface of the tumor, causing bleeding, will lead to the urine become brown, usually painless hematuria, may also be accompanied by urination difficulties and other symptoms. Urine brown, excluding physiological factors, it is recommended to seek medical examination and treatment as soon as possible to avoid delay.