Your kidneys filter waste from your blood to make urine. Normally, red blood cells stay in your bloodstream. When something damages your urinary tract, blood cells can leak into urine. This can happen anywhere along the urinary system: kidneys, ureters, bladder, or urethra.
The most common causes fall into three categories:
Other causes include intense exercise, medications, or genetic factors. In men, prostate problems may contribute. In women, menstrual blood can sometimes be mistaken for blood in urine.
See a doctor immediately if you notice:
While blood in urine often comes from harmless causes, it can sometimes indicate serious conditions like kidney disease or cancer. Doctors typically perform a physical exam, urine test, and imaging tests to determine the cause.
Many people assume blood in urine always means cancer. While it can be a sign, most cases come from less serious causes like UTIs or kidney stones. Another myth is that only dark red urine indicates blood - sometimes urine appears normal but contains microscopic blood.
Last year, I noticed my urine was slightly pink after an intense cycling session. I drank more water and rested, and the color returned to normal within 24 hours. However, if the discoloration had persisted or been accompanied by other symptoms, I would have seen a doctor immediately.