While it may be a sign of bladder cancer, thickening of the bladder does not necessarily indicate that cancer is present. The most common sign is blood in the urine; pain during urination, frequent urination and difficulty urinating may also occur, according to Cleveland Clinic.
Tumors typically form as a result of the rapid and dangerous transformations that cause cells to multiply out of control. Tumors may be malignant -cancerous- or benign -non-cancerous-, with both causing the bladder wall to thicken. Cigarette smoking more than doubles the risk of bladder cancer; prior radiation exposure is the next most common risk factor, explains Cleveland Clinic.