The urine is brown then the possible reasons: First, urine retention patients lead out brown urine, mostly related to the extreme concentration of urine. Secondly, patients suffering from acute pyelonephritis, suffering from kidney crush injury, or large burns can discharge brown urine, which contains more hemoglobin and therefore results in brown urine color. Third, patients with paroxysmal sleep hemoglobinuria can excrete brown urine. Fourth, fava bean disease, when the patient’s body lacks 6-phosphoglucose dehydrogenase, brown urine can appear when eating fava beans, mostly accompanied by nausea, dizziness, yellowing of the skin and eyes, etc. Fifth, when the wrong blood type is transfused, it can cause acute hemolysis, and then brown urine can appear, mostly with a history of blood transfusion. Sixth, hemolytic anemia or after strenuous exercise, can appear urine is dark brown, mostly related to the urine contains more hemoglobin.