Though in most cases the cause is unknown, in some patients it has been associated with the exposition to aromatic amines and treatment with systemic cyclophosphamide.
Hematuria (blood in urine) is the main signal. It appears in 85% of the cases and it usually is painless and presents clots. Bladder irritation symptoms (very frequent urination, itching, or pain) appear capriciously.
The typical symptoms are: