If the color of the urine that comes out is red, the possible causes: 1, due to taking drugs or food staining. For example, aminopyrine tablets, rifampin capsules, after taking the urine color will be red. The reason for bleeding includes acute infection of the urinary tract, infection that causes the mucous membrane of the urethra to break down causing bleeding, blood mixed in the urine can appear red. Or there are stones in the urinary tract, which cause local mucous membrane to break down and bleed, and blood mixed in the urine can appear red in color. If you are a senior patient, you may also have a tumor of the urinary system, the tumor itself necrosis, bleeding, or lead to destruction of the surrounding mucosa, bleeding, then there can be red urine, you need to go to the hospital for urinalysis, urinary system CT examination to exclude these causes. 3, exogenous blood into the urine, such as women during menstruation, there may be vaginal bleeding, mixed with the urine and manifested. This is not a pathology of the urinary system itself.