The NHS explains that bladder cancer occurs when there is a growth of abnormal tissue in the bladder lining.
If the cancerous cells are contained inside the lining of the bladder, doctors describe it as non-muscle-invasive bladder cancer (early bladder cancer) – this is the most common type of bladder cancer.
When the cancerous cells spread beyond the lining, into the surrounding bladder muscle, it’s referred to as muscle-invasive bladder cancer (or invasive bladder cancer) – this is less common, but has a higher chance of spreading to other parts of the body.
The most common symptom of bladder cancer is blood in the urine, which although usually painless can cause a sudden urge to urinate and a burning sensation when passing urine.