About the bladder

The bladder is a hollow, muscular, balloon-like organ that collects and stores urine. It sits in the lower part of the tummy (abdomen), called the pelvis.

The inside of the bladder is covered with a urine-proof lining called the urothelium. This stops urine from being absorbed back into the body. The cells that make up this lining are called urothelial cells or transitional cells.

Urine is made in the kidneys. It travels to the bladder through tubes called ureters. Urine is made up of water and waste products that the body doesn’t need.

When the bladder is full, it sends messages (nerve signals) to the brain. This makes you feel like you need to empty your bladder.

The bladder muscle contracts and squeezes the urine out of the body through the urethra. In women, the urethra is a short tube that lies in front of the vagina. In men, the urethra is longer and passes through the prostate gland to the tip of the penis.

Position of the bladder in the body
Position of the bladder in the body

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What is cancer?

Cancer starts when cells in our bodies become abnormal. The abnormal cells grow and divide and can form a tumour.

Cancer and cell types

Cancers are grouped into types. Types of cancer often behave and respond to treatments in different ways.

Types of bladder cancer

There are different types of bladder cancer. The most common is urothelial bladder cancer, which is also called transitional cell carcinoma.

Why do cancers come back?

Sometimes, tiny cancer cells are left behind after cancer treatment. These can divide to form a new tumour.