Bladder cancer starts when the cells in the bladder begin to grow out of control. As the cells continue to grow uncontrollably, they build up to form a tumor.

Most bladder cancers start in the innermost lining of the bladder and grow outward. As the cancer grows, it becomes more advanced. The cancer may grow through the bladder wall and into pelvic or abdominal wall. It may also travel to nearby lymph nodes, or spread into more distant lymph nodes or other parts of the body, most commonly the lungs, liver, or bones. When this happens, it’s considered stage 4 bladder cancer.

What is the bladder?

The bladder is a hollow organ that sits in the pelvis. It’s flexible and made of muscle, and is responsible for storing urine before it leaves the body. The bladder is made up of several layers, each containing different types of cells.

The bladder is connected to the kidneys by tubes called ureters. The ureters let urine produced by the kidneys pass into the bladder for storage. When the muscles of the bladder contract during urination, urine then leaves the bladder through a tube called the urethra.

How is bladder cancer diagnosed?

Many different exams and tests may be used to diagnose bladder cancer. These tests include the following:

Internal exam

During this exam, a physician will physically examine the vagina or rectum to feel for lumps around the bladder.


This is an exam of the contents and appearance of urine for things such as proteins and red or white blood cells.

Urine cytology

In this exam, the urine is looked at under a microscope for abnormal or cancerous cells.


This involves physically looking into the bladder for tumors using a very thin instrument with a viewing lens on it.


During a biopsy, a small portion of bladder tissue is removed and examined under a microscope. This exam can be done during a cystoscopy and is used to diagnose cancer cells.

Other imaging tests, such as X-rays or CT scans, may be used to see if the cancer has metastasized, or spread to other parts of the body.

How does bladder cancer metastasize?

Cancer cells metastasize, or spread, when they break off from the original tumor and travel somewhere else in the body. Cancer cells can travel through our bodies in three different ways:

  • Cancer cells can spread to nearby lymph nodes, which let them enter the lymph system, where they can travel.
  • Cancer cells can break off of the original tumor and enter the bloodstream, where the cells move through the body in your blood.
  • Cancer cells can grow into nearby tissue through direct physical contact.

Even when a cancer metastasizes, the metastatic tumor is still the same type of cancer as the original tumor. For example, if bladder cancer metastasizes to the lungs, it’s still bladder cancer that has traveled to and grown in the lung tissue.

Are there risk factors for bladder cancer?

The following factors can increase your risk for being diagnosed with bladder cancer:

  • tobacco use, especially cigarettes
  • certain genetic changes related to bladder cancer
  • exposure to certain chemicals
  • previous radiation to the pelvis
  • certain herbs, such as Aristolochia fangchi
  • drinking water with high levels of arsenic or that has been treated with chlorine
  • having a family history of bladder cancer or a personal history of bladder infections
  • long-term use of urinary catheters

What are the symptoms of bladder cancer?

The symptoms of bladder cancer will vary from person to person. If you begin to experience blood in the urine, frequent or painful urination, or lower back pain, talk to your doctor. Other more common things can cause these symptoms, but they shouldn’t be ignored.