The bladder is a hollow organ in the lower abdomen. It stores
urine, the liquid waste made by the kidneys. The wall of the
bladder has three layers: the inner, middle, and the outer
layers. The bladder is part of the urinary tract. Urine passes
from each kidney into the bladder through a long tube called a
ureter. Urine leaves the bladder through a short tube called the
urethra. Bladder cancer starts in cells, the building blocks
that make up the bladder and the other organs of the body.
Bladder cancer begins when a normal cell becomes abnormal.
Normal cells grow and divide to form new cells as the body needs
them. When normal cells grow old or get damaged, they die, and
new cells take their place. Sometimes, this process goes wrong.
New cells form when the body doesn't need them, and old or
damaged cells don't die as they should. The buildup of extra
cells often forms a mass of tissue called a growth or tumor.
Tumors in the bladder can be benign (not cancer) or malignant
(cancer). Benign tumors are not as ha