Urine a little red may be caused by normal physiological factors, may also be urinary stones, urinary tract tumors and other pathological factors. 1. Physiological factors: normal people in the food rich in red pigment can lead to excrement is also red, such as consumption of dragon fruit, amaranth, etc. can appear after the urine a little red. 2. urinary stones: due to urinary stones directly stimulate and damage the urethral mucosa caused by bleeding, blood and urine mixed with a little red urine. 3. Urinary tumor: urinary tumor invades the blood vessels of urethral mucosa, causing blood vessels to rupture and bleed, or tumor tissue necrosis and shedding with the urine, which can lead to a little redness in the urine. There may be other reasons for the redness of urine, it is recommended to actively consult a professional physician under the guidance of diagnosis and treatment.