Bladder cancer is cancer of the urinary bladder.
Your bladder is where urine is stored. It is a hollow organ, the size of a small balloon, in the lower part of the abdomen. The bladder has a muscular wall that allows it to get larger and smaller. Urine is the liquid waste that is made by the kidneys when they clean the blood. The urine passes from the two kidneys into the bladder through tubes called ureters.