Retroperitoneal fibrosis is a rare condition that’s also known as Ormond’s disease. It occurs when excess fibrous tissue develops in the space behind your stomach and intestine called the retroperitoneal area.

Fibrosis is the growth of excess connective tissue, which causes a mass to form. This often causes compression and blockage of the ureters, which are the tubes that carry urine from your kidneys to your bladder.

Tissue masses can block one or both of your ureters. When urine backs up in the ureters, harmful materials can build up in your blood, and kidney damage can result. The disease can cause kidney failure if it isn’t treated.

The condition typically starts with inflammation and fibrosis of the abdominal aorta. The abdominal aorta is the large artery that brings blood from your heart to the areas below your kidneys.

As the disease progresses, it affects the arteries that carry blood to your legs and kidneys. Pain, leg swelling, and a reduction in kidney function can occur.

This disorder results in decreased blood flow from the aorta to the lower part of your body. Initially, your body reacts to the reduced blood flow. Symptoms that occur in the early stages of this condition include:

  • dull pain in the abdomen or back that may be hard to pinpoint
  • pain on one side between your upper abdomen and back
  • leg pain
  • discoloration in one or both legs
  • swelling of one leg
  • intense abdominal pain with bleeding or hemorrhaging

Other symptoms may arise as the disease progresses, but certain symptoms can occur at any stage. They include:

  • severe abdominal or back pain
  • appetite loss
  • weight loss
  • fever
  • nausea or vomiting
  • an inability to urinate
  • reduced urine production
  • impaired limb movement
  • an inability to think clearly
  • a low level of red blood cells, which is called anemia
  • kidney failure

You should see your doctor if you have reduced urine output with abdominal or lower back pain. These can be symptoms of kidney damage.

According to the National Organization for Rare Diseases, the exact cause of this condition is unknown in about two-thirds of cases.

Age and gender are the greatest risk factors for the disease. According to the National Center for Biotechnology Information, it occurs most often between the ages of 40 and 60. However, it can develop at any age. The condition occurs twice as often in men as in women.

Specific conditions linked with retroperitoneal fibrosis can include:

The disorder can also be associated with:

  • recent surgery on the abdomen or pelvis
  • the use of cancer treatments involving external beam radiation
  • certain medications to treat migraines and high blood pressure

The complications associated with this disease vary. The size and location of the excess tissue growth can cause damage to various areas served by the abdominal aorta.

If this condition goes untreated, serious problems result from swelling and blockage of the ureters. This may result in chronic kidney failure and long-term blockage of the ureters, which can cause urine backup and kidney swelling.

Untreated retroperitoneal fibrosis can also lead to the cutting off of the blood supply to the legs, which in turn can lead to further dangerous complications.

An accurate diagnosis requires the use of CT or MRI scans of your abdomen.

Additional tests used to confirm the diagnosis include:

  • blood tests to measure kidney function, anemia, and inflammation
  • an X-ray of the kidneys and ureters, which is called an intravenous pyelogram
  • an ultrasound of the kidneys
  • a biopsy to check for cancer cells

Treatment varies depending on the severity and location of the fibrosis. If you’re diagnosed in the early stages of the condition, you may be prescribed anti-inflammatory medications, corticosteroids, or immunosuppressants.

If you’re diagnosed after fibrosis has blocked one or both of your ureters, your doctor will need to clear the obstruction.

This is done by draining the urine with a stent, or drainage tube, inserted through your back and into your kidney. A stent may also be run from your bladder through the ureter into the kidney.

In some cases, surgery may be required. It may be used to:

  • free the affected ureter from the fibrosis
  • wrap the affected ureter in fat tissue from the intestines to protect it from fibrosis regrowth
  • reposition the affected ureter away from the inflammation to prevent the blockage from happening again

The goals of treatment are to remove the blockage, repair the affected ureter, and prevent it from happening again. For many people, treatment requires both medication and internal intervention.

If the condition is diagnosed and treated at an early stage, the long-term outlook for patients can be very good. When kidney damage is minimal and surgery is successful, there’s a 90 percent chance of long-term success.

However, in cases where the kidneys are severely affected, damage can be permanent, leading to the need for a kidney transplant.

The majority of cases cannot be linked to any specific cause, so prevention may not be possible.

However, the condition is associated with the use of some medications to treat high blood pressure and medications to treat migraines called ergotamines. Ask your doctor about the possible side effects of these types of drugs and whether alternatives are available.