Bladder cancer is where a growth of abnormal tissue, known as a tumour, develops in the bladder lining. In some cases, the tumour spreads into the surrounding muscles.
The most common symptom of bladder cancer is blood in your urine, which is usually painless.
If you notice blood in your urine, even if it comes and goes, you should visit your GP, so the cause can be investigated.
Read about the symptoms of bladder cancer.
Types of bladder cancer
Once diagnosed, bladder cancer can be classified by how far it has spread.
If the cancerous cells are contained inside the lining of the bladder, doctors describe it as non-muscle-invasive bladder cancer. This is the most common type of bladder cancer, accounting for 7 out of 10 cases. Most people don't die as a result of this type of bladder cancer.
When the cancerous cells spread beyond the lining, into the surrounding muscles of the bladder, it's referred to as muscle-invasive bladder cancer. This is less common, but has a higher chance of spreading to other parts of the body and can be fatal.
If bladder cancer has spread to other parts of the body, it's known as locally advanced or metastatic bladder cancer.
Read more about diagnosing bladder cancer.
Why does bladder cancer happen?
Most cases of bladder cancer appear to be caused by exposure to harmful substances, which lead to abnormal changes in the bladder's cells over many years.
Tobacco smoke is a common cause and it's estimated that half of all cases of bladder cancer are caused by smoking.
Contact with certain chemicals previously used in manufacturing is also known to cause bladder cancer. However, these substances have since been banned.
Read more about the causes of bladder cancer and preventing bladder cancer.
Treating bladder cancer
In cases of non-muscle-invasive bladder cancer, it's usually possible to remove the cancerous cells while leaving the rest of the bladder intact.
This is done using a surgical technique called transurethral resection of a bladder tumour (TURBT). This is followed by a dose of chemotherapy medication directly into the bladder, to reduce the risk of the cancer returning.
In cases with a higher risk of recurrence, a medication known as Bacillus Calmette-Guérin (BCG) may be injected into the bladder to reduce the risk of the cancer returning.
Treatment for high-risk non-muscle-invasive bladder cancer, or muscle-invasive bladder cancer may involve surgically removing the bladder in an operation known as a cystectomy.
When the bladder is removed, you'll need another way of collecting your urine. Possible options include making an opening in the abdomen so urine can be passed into an external bag, or constructing a new bladder out of a section of bowel. This will be done at the same time as a cystectomy.
If it's possible to avoid removing the bladder, or if surgery is not suitable, a course of radiotherapy and chemotherapy may be recommended. Chemotherapy may sometimes be used on its own before surgery or before being combined with radiotherapy.
After treatment for all types of bladder cancer, you'll have regular follow-up tests to check for signs of recurrence.
Read more about treating bladder cancer.
Who is affected?
About 10,000 people are diagnosed with bladder cancer every year and it's the seventh most common cancer in the UK.
The condition is more common in older adults, with more than half of all new cases diagnosed in people aged 75 and above.
Bladder cancer is also more common in men than in women, possibly because in the past, men were more likely to smoke and work in the manufacturing industry.