A urinoma is a collection of urine that forms in the space where your abdominal organs sit. It usually develops when you have a condition that has led to urinary obstruction. Instead of flowing out of your urethra as it should, urine flows back into your retroperitoneum, the space inside your abdomen.
A urinoma is a collection of urine (pee) that forms in the retroperitoneum. The retroperitoneum is the space in the body where your abdominal organs sit. It's behind the peritoneum, the tissue that lines your abdominal wall and covers most of the organs there, such as your intestines, stomach, liver and bladder.
Urinomas form when pee flows irregularly, entering the retroperitoneum and combining with fat. They usually form because of a blockage that causes some of the pee to flow backward, leaking into the retroperitoneum.
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When you eat, your body takes in the energy and nutrients it needs, then leaves behind waste products. Your urinary system eliminates the liquid waste products through pee. In a functioning urinary system:
Urinomas form in the retroperitoneum, the back portion of your abdomen.
Extravasation of urine refers to when pee doesn’t flow as it should. Instead of exiting the body through the urethra, some of it collects in other body cavities, such as the retroperitoneum.
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People with a urinoma may feel a noticeable mass in their abdomen. They may also experience:
Urinomas usually occur because of a condition that causes a urinary obstruction, such as:
Urinomas may also develop after surgery on your abdominal organs or urinary system.
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Your healthcare provider uses tests to diagnose a urinoma, including:
There’s no guaranteed way to prevent a urinoma. But you can reduce your risk of a urinary obstruction by practicing healthy bladder habits. You may:
Many urinomas are small and don’t interfere much with your daily activities. Larger urinomas are often the result of an underlying condition that causes a urinary obstruction. Many people don’t have further problems with urinomas after they receive treatment for the underlying condition.
If you have a urinoma or think you could, you may also want to ask your healthcare provider:
A note from Cleveland Clinic
A urinoma is a collection of urine that forms in the back of your abdomen. It usually develops because of urinary obstruction. Urinomas form when your pee doesn’t flow out of the urethra as it should. Instead, some pee flows back into the retroperitoneum. Small urinomas usually don’t need any specific treatment. Your healthcare provider may drain a large urinoma and treat any underlying condition that caused it.
Last reviewed on 08/29/2022.
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Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy