Loin Pain Hematuria Syndrome: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 23, 2026.
What kind of doctor treats loin pain hematuria syndrome?
Loin pain hematuria syndrome, a condition that causes ongoing flank pain with blood in the urine, is usually managed together by a nephrologist (kidney doctor) and a urologist (urinary tract doctor). A primary care doctor can also help coordinate care and manage pain between specialist visits. Testing rules out other kidney and urinary problems before this diagnosis is confirmed.
What is loin pain hematuria syndrome?
Loin pain hematuria syndrome, called LPHS for short, is a rare pain syndrome that is not well understood. It causes severe flank pain on one or both sides. Flank pain is pain in the side of the back, also called loin pain. The pain comes with hematuria, which means blood in the urine. The blood may be too small an amount to see, or it may be visible.
Symptoms
The main symptoms are:
- Severe pain in the flank, on one or both sides. It can last for minutes or be a constant ache, and it can happen once or twice a year or all the time.
- Pain that can spread to the lower belly, the front of the thigh, or the groin.
- Blood in the urine that you can see, or that shows up only on urine tests.
Visible blood in the urine is usually linked to worse pain. Between episodes, the blood may show up only on tests, or it may clear completely even though the pain stays. Many people have a normal physical exam, and most have normal kidney function.
Causes and who gets it
The cause is not known. Several ideas have been suggested, but none has pinpointed the actual cause. Disease of the kidney's blood vessels was once thought to be a cause. Newer scans of those blood vessels usually look normal. In some people, a kidney inflammation such as IgA nephropathy is behind the symptoms. Only a kidney biopsy can tell these cases apart. Many people with LPHS have had kidney stones.
Most people who get LPHS are young women. Most people have symptoms by their 20s. LPHS is not known to cause kidney injury or raise the risk of death.
How doctors diagnose it
LPHS is a diagnosis of exclusion. This means doctors rule out other causes first. Many people go unrecognized for years and see several doctors. Doctors have not agreed on one set of official criteria. One set of minimal criteria is blood in the urine and pain for at least 6 months that kidney stones do not explain.
Tests can include:
- A urine culture, to rule out infection, and a urinalysis, to check for kidney filter disease.
- A cystoscopy or CT scan, to look for kidney stones, tumors, or cysts.
- Angiography or CT angiography, scans of the blood vessels, to look for vessel problems.
- A kidney biopsy, if there are signs of kidney filter disease.
Treatment
Because the cause is unknown, treatment aims to relieve symptoms. Options include simple pain relievers, opioid pain medicines, and kidney autotransplantation. Patients usually start with non-opioid pain relievers and may move to stronger opioid medicines. Many people on high-dose opioids end up becoming addicted.
Some people have a period of remission, when the symptoms go away on their own. For this reason, doctors usually start with gentler treatments before more invasive ones. There is limited evidence that blood pressure medicines called ACE inhibitors or ARBs may reduce the pain and the blood in the urine. Nerve stimulation and nerve blocks have helped in some cases, but none gave long-term pain relief.
Kidney autotransplantation is surgery that removes the kidney and places it in the lower belly on the same side. It should not be the first treatment and should not be offered to all patients. It is for people with severe pain that other treatments have not controlled. Complications can include loss of the transplanted kidney, wound infection, and nerve entrapment. The pain can return after surgery in some people.
When to see a doctor
Never ignore blood you see in your urine. Get checked by your provider. Contact your provider right away if you cannot urinate or you pass blood clots in your urine. Also contact your provider right away if blood in the urine comes with fever, vomiting, or shaking chills. Call 911 or go to the emergency room if you have trouble breathing, faint, are confused, or have bleeding that will not stop.
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 can order first urine tests, look for common causes such as infection or stones, and refer you to a kidney doctor or urologist. They can also help manage pain and coordinate care between specialist visits.
Common questions
What causes loin pain hematuria syndrome?
The exact cause of loin pain hematuria syndrome is not fully understood. Doctors first rule out other causes of flank pain and blood in the urine, such as stones or infection.
How quickly can I be seen for loin pain hematuria syndrome?
How fast you can be seen depends on the office you choose, so call the office to ask about openings. Never ignore blood you see in your urine, and get checked by your provider.
Is loin pain hematuria syndrome dangerous?
Loin pain hematuria syndrome is not known to cause kidney damage or raise the risk of death, but the pain can be severe. Doctors rule out other kidney disease first, because LPHS is diagnosed only after other causes are excluded.
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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.
