Basically, Causes can be divided according to the affected organ and they are Kidney
conditions (infection, pyelonephritis, kidney stones
, polycystic kidney
disease), Bladder conditions (cystitis, bladder polyp, bladder tumor), Urethral conditions (Sexually transmitted diseases, urethral injury, vaginal inflammation), and certain bleeding disorders
I feel that without clinical examination, pinpointing a diagnosis is tough. Also a complete urine examination and culture may be required.