Potential causes of blood in the urine are an enlarged prostate gland, a urinary tract infection, a kidney infection, kidney disease and cancer, states Mayo Clinic. Additional causes include a bladder or kidney stone, certain inherited disorders, kidney injury, medications, and strenuous exercise.
Blood in the urine is referred to as hematuria, which occurs when part of the urinary tract or kidneys allows blood cells to leak into the urine, as Mayo Clinic explains. Penicillin and other drugs can cause urinary bleeding, and any anticoagulant combined with an existing disorder causes additional bleeding.
Urine that is pink, red or cola-colored is a sign of hematuria. Bleeding may be painless, although passing blood clots may cause pain. Urinary blood may only be visible under a microscope. Hematuria can occur without the presence of other symptoms. Someone who notices blood in the urine should see a physician, according to Mayo Clinic.
Ex-lax, a laxative medication, can cause the urine to look red, states Mayo Clinic. Additionally, foods like beets, berries and rhubarb can cause the urine to appear red. However, blood in the urine is visibly distinct from simply red urine. Red urine caused by foods or medication may go away in a few days' time.