Retroperitoneal Fibrosis: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor treats Retroperitoneal Fibrosis?
A primary care doctor is often the first to suspect the problem and order early tests. Treatment usually involves a team: a nephrologist, a kidney specialist, manages kidney function and medicines; a urologist treats the urinary tract and may place stents or perform surgery; and a rheumatologist treats immune system diseases.
What it is
Retroperitoneal fibrosis is a rare condition in which soft, fibrous scar tissue grows in the space behind your stomach and intestines, called the retroperitoneum. This space holds organs such as the kidneys and the tubes that carry urine from the kidneys to the bladder. As the scar tissue builds up, it can press on these tubes, causing urine to back up and harm the kidneys over time.
Symptoms
Many people have no symptoms at first, which is one reason the condition is often found late. When symptoms do appear, they often include a dull pain in the side, back, or lower belly. Some people feel tired, lose weight without trying, or run a low fever. If the urine tubes are squeezed, the kidneys may not work as well as they should, and swelling in the legs can happen when large blood vessels are pressed.
Causes and who gets it
In many cases the cause is unknown, which is called idiopathic retroperitoneal fibrosis. It is thought to involve the immune system reacting in an unusual way. Some medicines, infections, injuries, and certain cancers have also been linked to it. The condition is rare and is more common in men and in people over about 40.
How doctors diagnose it
Doctors usually start with imaging scans, such as a CT scan or MRI, to look for the scar tissue. Blood and urine tests check how well the kidneys are working and look for signs of inflammation. A biopsy may be taken to rule out cancer or another condition.
Treatment
Treatment aims to shrink the scar tissue and protect the kidneys. Medicines such as corticosteroids or drugs that calm the immune system are often used. If urine is backing up, a small tube called a stent may be placed to keep the urine tubes open. Some people need surgery to free the squeezed tubes from the scar tissue.
When to see a doctor
See a doctor if you have ongoing pain in your side, back, or lower belly, especially with tiredness, fever, or weight loss. Get medical care sooner if you notice less urine than usual, blood in your urine, or swelling in your legs.
How a direct primary care or concierge doctor fits in
A direct primary care doctor charges a flat monthly fee instead of billing insurance, while a concierge doctor usually charges more and often works alongside insurance. Either one can be a steady partner for a rare condition like this, ordering tests, watching kidney results, and coordinating specialist referrals.
Common questions
Is retroperitoneal fibrosis cancer?
No, the scar tissue itself is not cancer. However, doctors often do a biopsy because some cancers can look similar on scans.
Can it go away on its own?
It usually does not go away without treatment. Some people improve with medicine, while others need procedures or surgery.
Does it always damage the kidneys?
Not always. Early treatment can often protect kidney function before lasting harm happens, which is why finding it early matters.
Will I need surgery?
Some people do, especially if the urine tubes are badly squeezed. Many people are managed with medicines and stents instead.
Sources
- NIH Genetic and Rare Diseases Information Center - IgG4-related retroperitoneal fibrosis
- MedlinePlus - Retroperitoneal fibrosis
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
