Duplex Kidney (Duplicated Ureters)

Duplex kidney, also called duplicated ureters, is a congenital (present-at-birth) condition where two ureters drain pee from a single kidney. Most people don’t have symptoms or need treatment. Surgery is effective at treating complications that cause symptoms.


Image shows incomplete duplex kidney or two ureters joining before the bladder, and duplex kidney, two separate ureters.
The two ureters in a duplex kidney can meet before joining the bladder (partial/incomplete duplication) or enter the bladder separately (complete duplication).

What is a duplex kidney?

Duplex kidney is a condition you’re born with (congenital) where you have two ureters (tubes) — instead of one — that connect one of your kidneys to your bladder. It happens early in development, while your kidneys and ureters are forming. Duplex kidney is also called duplicated ureters or duplicated collecting system.

Ureters are tubes that drain pee (urine) from your kidneys to your bladder. Normally, one ureter leads separately from each of your two kidneys to your bladder. In duplicated collecting systems, two ureters — one in the upper part and one in the lower part — drain a single kidney.

Types of duplex kidney

Kidney duplication may affect one or both kidneys (bilateral duplex kidneys). It can also be complete or incomplete.

  • Complete duplex kidney: Two separate ureters lead away from the same kidney and enter your bladder separately.
  • Incomplete duplex kidney: Two separate ureters lead away from the same kidney but join together before draining into your bladder. This forms a single ureter when it enters your bladder.


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Symptoms and Causes

What are the symptoms of duplex kidney (duplicated ureters)?

For most people, duplex kidneys don’t cause symptoms. Symptoms happen when the ureters don’t drain normally into your bladder (more common with complete duplex kidneys). Symptoms of duplex kidney complications include:

Do duplex kidneys make you pee more?

No, duplex kidneys don’t cause more pee to drain into your bladder or increase how much you pee. Other body systems control the amount of pee you produce. But if you have a duplex kidney, you might get UTIs frequently, which can cause you to feel like you have to pee more often than you normally would.

What causes duplex kidneys?

When a fetus is developing, cell division errors can cause a duplex kidney. There’s no evidence that anything you do or don’t do during pregnancy causes duplex kidneys.

Is duplex kidney inherited?

Yes, sometimes duplex kidney can be inherited (if a parent has it, their child might have it, as well). If one parent has a duplex kidney, any biological children have a 50% chance of being born with it. But kids can have a duplex kidney even if neither of their parents has the condition.


What are the complications of duplex kidneys?

Duplex kidneys usually cause symptoms only when you have other, related differences in the way your urinary system develops. These differences can lead to blockage of the flow of pee (causing it to build up), swelling (hydronephrosis) and/or pee flowing backwards toward your kidneys (reflux). Any of these conditions can lead to repeated UTIs.

Conditions associated with duplex kidney include:

Diagnosis and Tests

How is duplex kidney (duplicated ureters) diagnosed?

Healthcare providers can see duplicated ureters on imaging tests that get pictures of your urinary tract. While trying to determine what’s causing your symptoms, your provider might ask you about:

  • Back or stomach pain.
  • If you have issues with leaking pee (incontinence).
  • Family health history (if anyone else in your biological family has a duplex kidney).

Duplicated ureters are usually found during childhood if they’re causing UTIs or incontinence. Some people don’t know they have them until they’re adults — providers might find them while diagnosing a different condition. Symptoms can be similar to other health issues, making it difficult to diagnose.

What tests will be done to diagnose this condition?

Your provider might perform the following imaging tests to diagnose a duplex kidney:


Management and Treatment

How is duplex kidney treated?

Most people don’t need treatment for a duplex kidney. But if you have an ectopic ureter or another issue that’s causing symptoms, you might need surgery on your kidneys, bladder or ureters.

Can duplex kidney be removed?

Providers rarely remove a duplicated kidney. If kidney duplication is causing symptoms, surgical options include:

  • Ureteroureterostomy: A surgeon joins the two ureters to make one Y-shaped ureter that drains into your bladder.
  • Ureteral reimplantation: A surgeon makes a new entry into your bladder for an ectopic or refluxing ureter. This allows pee to drain correctly and not flow backwards.
  • Nephrectomy: A surgeon removes some or all of your kidney that’s not working correctly. This can relieve incontinence and decrease your risk of infection. This treatment is uncommon — providers only perform it when one kidney isn’t functioning well or is causing issues, and the other kidney is operating normally.

How long does it take to recover from surgery?

The amount of recovery time you’ll need after surgery depends on your age and which procedure you had. For instance, kids usually stay in the hospital for one to two days for recovery, then continue to rest at home for one to two weeks.

A provider will perform a follow-up ultrasound of your kidney after surgery.

Outlook / Prognosis

What can I expect if I have a duplex kidney?

Most people with a duplex kidney don’t have any issues. But if you have conditions like urinary incontinence, pee backing up in your ureter (reflux) or frequent UTIs, you might need corrective surgery.

How serious is a duplex kidney?

Having a duplex kidney usually isn’t serious or dangerous. Most people have no symptoms and don’t need treatment.

Can I live a normal life with a duplex kidney (duplicated ureters)?

Duplex kidney isn’t life-threatening and treatments — if you need them — are usually effective at resolving any symptoms.

Living With

How do I take care of myself?

If you know you or your child has a duplex kidney, keep an eye out for symptoms of conditions that affect your urinary tract (like repeated UTIs with fevers or leaking pee). If you or your child has surgery, be sure to follow all of your healthcare provider’s instructions exactly.

When should I see my healthcare provider?

Contact your healthcare provider if you have a duplex kidney diagnosis and have symptoms you think might be related. Ask them what new or worsening symptoms to look out for.

When should I go to the ER?

Go to the ER if you have symptoms of a serious infection, including:

  • High fever (over 102 degrees Fahrenheit or 39 degrees Celsius).
  • Severe side pain that comes on suddenly.
  • Repeated vomiting and inability to drink or eat anything

What questions should I ask my doctor?

It might be helpful to ask your healthcare provider:

  • Are there any medications I should take?
  • Which kind of duplex kidney do I have?
  • Do I need surgery? What kind?
  • Do I need to see a specialist?
  • Do I need a referral to see a specialist?
  • Do you think my symptoms will go away on their own?
  • If I have duplex kidney, should I have my child tested?

Additional Common Questions

How common is duplex kidney?

Kidney duplication is the most common birth defect (congenital condition) that affects your urinary tract. About 1 in 125 people have either complete or incomplete kidney duplication.

A note from Cleveland Clinic

Duplex kidney (duplicated ureters) isn’t a life-threatening condition and doesn’t usually cause symptoms. Many people don’t even know they have it. If you or your child is diagnosed with a duplex kidney and has symptoms, treatment is usually effective at resolving them. While it can be embarrassing to discuss issues like leaking pee or pain when you go to the bathroom, make sure you talk to a healthcare provider about any symptoms — they’re there to help. They can work with you to get to the bottom of your symptoms and recommend treatment to get you feeling better.

Medically Reviewed

Last reviewed on 02/12/2024.

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