Why does upper tract urothelial cancer cause blood in urine?

The urothelium is the delicate inner lining of the renal pelvis and ureter, which carry urine from the kidney to the bladder. A cancer arising there may have a fragile surface or irritate nearby small blood vessels. Blood can then mix with urine, sometimes making it pink, red, or tea-coloured; at other times it is found only on a urine test. Blood in Urine is a very common presentation of Upper Tract Urothelial Cancer. Blood in urine also has many causes besides cancer, including infection, stones, injury, and some medicines.

Arrange a prompt medical assessment for any visible blood in urine, even if it settles. The clinician may ask about pain, clots, smoking history, medicines, and prior urinary problems. Assessment can include a urine sample to look for blood or infection, blood tests, imaging of the urinary tract, and a camera examination of the bladder when appropriate. Keep note of when the colour change began and whether it comes and goes.

Seek urgent care if you cannot pass urine, pass large clots, have severe flank or abdominal pain, feel faint, or have fever with shaking chills. These symptoms can signal obstruction, substantial bleeding, or infection that needs timely treatment. Contact a clinician promptly for recurrent visible bleeding or a new change in urine colour.

Ask what may be causing the bleeding, which tests are suitable for the upper urinary tract, and how quickly results will be available. If an abnormality is found, ask where it is located, whether a specialist referral is needed, and which symptoms should prompt urgent contact.