Uterine fibroids can cause blood in urine, but the scenario is uncommon and typically involves a large or unusually positioned fibroid that has begun to physically affect the bladder or the tubes connecting the kidneys to the bladder. The far more typical urinary complaints from fibroids are frequent urination, urgency, and nighttime trips to the bathroom. When hematuria (the medical term for blood in urine) does appear alongside fibroids, it usually signals one of a handful of specific complications that deserve prompt investigation rather than a wait-and-see approach.
The More Common Urinary Problems Fibroids Cause
Before getting into the rarer scenario of blood in the urine, it helps to know just how often fibroids bother the urinary tract in general. A 2025 systematic review pooling data from multiple studies found that roughly half of women with uterine fibroids reported some form of lower urinary tract symptoms.1PubMed Central. Lower Urinary Tract Symptoms in Uterine Myoma: A Systematic Review and Meta-Analysis The most frequently reported issues were urinary frequency, stress incontinence, and nocturia. A separate study focused on the relationship between fibroid location and symptoms found nocturia in about nine out of ten patients, urgency in close to six out of ten, and incontinence in roughly half.2PubMed. Lower urinary tract symptoms in patients with uterine fibroids: association with fibroid location and uterine volume
These symptoms happen because the uterus sits directly in front of the bladder. A fibroid growing on the front wall of the uterus, or one that grows large enough regardless of its position, can press against the bladder, reducing its capacity and irritating the muscle wall. The bladder essentially gets squeezed, so it holds less urine and signals “full” more often. That mechanical pressure explains why frequency, urgency, and incontinence dominate the symptom picture rather than bleeding into the urinary tract.
Blood in the urine requires something beyond simple compression. It requires tissue damage, obstruction severe enough to injure the kidneys or ureters, or an abnormal connection forming between the uterus and the bladder. Each of these pathways is genuinely rare, but each is well documented.
When a Fibroid Physically Invades the Bladder
The most direct way a fibroid causes blood in the urine is by eroding through the uterine wall and into the bladder itself. This is an unusual event, and when it happens it tends to involve a fibroid that has undergone calcification or degenerative changes over many years. A published case report describes a 55-year-old postmenopausal woman who had known uterine fibroids and presented with pelvic pain, hematuria, and recurrent bladder stones. Imaging revealed a calcified uterine mass that had invaded through the bladder dome. Pathology confirmed a benign fibroid with focal degeneration and calcification, while the bladder tissue showed inflamed granulation tissue with calcification.3Journal of Case Reports and Images in Obstetrics and Gynecology. Erosion of calcified uterine leiomyoma into the urinary bladder: A case report
What makes this pathway distinctive is the combination of symptoms. Hematuria from direct invasion often comes alongside bladder stones, because the calcified fibroid material that breaks through into the bladder can seed stone formation. The blood in the urine may be visible to the naked eye or detected only on a urinalysis. Pelvic pain is common, and the pattern tends to be chronic and worsening rather than sudden. The key diagnostic tools are CT and MRI, which can show the mass bridging the uterine and bladder walls.
This type of erosion tends to develop over years, often in fibroids that were never treated or monitored. It is most often reported in postmenopausal women, possibly because declining estrogen levels promote calcification and degenerative changes in fibroids that were present for decades. Still, it is genuinely rare even among women with long-standing untreated fibroids.
Ureteral Obstruction and Kidney Pressure
A second pathway involves the ureters, the narrow tubes that carry urine from each kidney down to the bladder. A large fibroid, particularly one growing from the lower portion of the uterus or from the broad ligament, can press against one or both ureters and partially or fully block urine flow. When urine backs up, the kidney swells, a condition called hydronephrosis. That swelling and the back-pressure it creates can damage kidney tissue and lead to blood appearing in the urine.
Case reports illustrate how serious this can become. One published case described a woman with a 20-centimeter fibroid that was discovered only after she sought care for high blood pressure. Investigation revealed bilateral hydronephrosis, meaning both kidneys were swollen from ureteral blockage caused by the mass.4PubMed Central. Arterial hypertension as an inaugural sign of myomatous uterus Another case involved a 33-year-old woman with a posterior fibroid measuring nearly 20 centimeters. Along with heavy menstrual bleeding and urinary frequency, she had a creatinine level of 4.0 mg/dL, indicating serious kidney impairment, alongside new-onset hypertension and severe bilateral hydronephrosis from ureteral obstruction.5PubMed Central. Bilateral Obstructive Uropathy From a Large Uterine Fibroid Causing Severe Renal Impairment: A Case Report
In both of these cases, the urinary obstruction was the presenting problem that ultimately led to discovery of the fibroid. The blood in urine from ureteral obstruction can be microscopic (picked up only on a lab test) or sometimes visible. What distinguishes this pathway is that it often presents with flank pain, elevated blood pressure, and signs of declining kidney function rather than isolated hematuria. A fibroid large enough to block the ureters is almost always palpable on physical exam or visible on imaging.
The concern with this pathway is that kidney damage can become irreversible if the obstruction goes unaddressed for a long time. When bilateral obstruction occurs, the situation is urgent because both kidneys are compromised simultaneously. Fortunately, relieving the obstruction, whether through fibroid removal or temporary ureteral stenting, often allows kidney function to recover if caught in time.
Fistula Formation Between the Uterus and Bladder
A vesicouterine fistula is an abnormal channel that forms between the uterus and the bladder. While most vesicouterine fistulas are caused by cesarean section or other pelvic surgery, fibroids can contribute to fistula formation, particularly when a fibroid presses against the bladder wall for a prolonged period and the tissue between the two organs breaks down. The hallmark symptom is cyclical hematuria, meaning blood appears in the urine on a monthly pattern that corresponds to the menstrual cycle. Menstrual blood, rather than flowing out through the vagina, drains through the fistula and into the bladder.
One reported case described a woman whose chief complaint was the absence of menstrual periods for three years. She was, however, experiencing cyclical hematuria accompanied by premenstrual symptoms like breast tenderness for the same time period, without any vaginal bleeding.6PubMed Central. Vesicouterine fistula presenting with cyclical haematuria mimicking bladder endometriosis: A case report Essentially, her menstrual flow had been entirely rerouted into the bladder through the fistula.
Cyclical hematuria is a strong clinical clue. If you notice blood in your urine that comes and goes in a monthly pattern and you have known fibroids, this possibility is worth bringing up with your doctor. The fistula can be confirmed with imaging studies or cystoscopy, where a camera is passed into the bladder to look for the abnormal opening. Surgical repair is typically required to close the fistula, and the fibroid usually needs to be addressed as well to prevent recurrence.
How Doctors Figure Out What Is Causing Blood in Your Urine
Blood in the urine has a long list of potential causes, and fibroids are far from the most common. Urinary tract infections, kidney stones, bladder infections, and bladder or kidney cancers are all more frequently responsible. If you have known fibroids and notice blood in your urine, that does not automatically mean the fibroids are the culprit. A proper workup is needed to rule out these other possibilities before attributing the bleeding to a fibroid.
The typical evaluation includes a urinalysis and urine culture to check for infection, imaging of the urinary tract (often a CT scan or ultrasound), and sometimes cystoscopy to directly visualize the inside of the bladder. If a fibroid is large, especially if it is in contact with the bladder wall on imaging, and no other cause of bleeding is found, the fibroid becomes a leading suspect. The pattern of bleeding matters too. Constant or worsening hematuria alongside pelvic pain and a large fibroid on imaging points toward erosion. Cyclical hematuria tracking with menstrual symptoms suggests a fistula. Flank pain, high blood pressure, and declining kidney labs suggest ureteral obstruction.
One diagnostic trap worth knowing about: endometriosis can also cause blood in the urine when it involves the bladder, and endometriosis and fibroids frequently coexist. Cyclical hematuria from bladder endometriosis can look very similar to cyclical hematuria from a vesicouterine fistula. The case report of a vesicouterine fistula cited earlier was initially mistaken for bladder endometriosis before the fistula was identified.6PubMed Central. Vesicouterine fistula presenting with cyclical haematuria mimicking bladder endometriosis: A case report Getting the diagnosis right matters because the treatments are different.
Fibroid Location and Size Matter More Than Having Fibroids at All
Not all fibroids are created equal when it comes to urinary tract effects. A small intramural fibroid sitting in the back wall of the uterus may never cause a single urinary symptom. A large anterior fibroid pressing directly on the bladder is far more likely to cause frequent urination and, in extreme cases, the complications described above. Research on lower urinary tract symptoms in fibroid patients has consistently found that the location of the fibroid relative to the bladder, and the total volume of the uterus, are better predictors of urinary symptoms than simply having fibroids.2PubMed. Lower urinary tract symptoms in patients with uterine fibroids: association with fibroid location and uterine volume
The fibroids documented in case reports of hematuria tend to be very large, often 15 centimeters or more. That does not mean a smaller fibroid can never cause blood in the urine, but it does mean the risk scales with size and proximity to urinary structures. A fibroid growing toward the bladder from the lower uterine segment or cervix, or one on the broad ligament near the ureter, poses more risk to the urinary tract than one growing upward from the top of the uterus.
This is why monitoring matters. Many women with fibroids are told their fibroids are small and asymptomatic, which is often true. But fibroids can grow over time, and a fibroid that was clinically insignificant five years ago may become a problem if it doubles or triples in size. Periodic imaging to track growth is especially worthwhile if you have fibroids located near the bladder or ureters.
What to Do If You Have Fibroids and See Blood in Your Urine
Visible blood in the urine always warrants a medical visit regardless of whether you have fibroids. Even microscopic hematuria detected on a routine urinalysis deserves follow-up. The most important step is not to assume your fibroids are the cause without investigation. Bladder cancer, kidney stones, and infections are more common reasons for hematuria and need to be excluded first.
If your evaluation points toward the fibroids as the source, the treatment depends on the mechanism. Ureteral obstruction often requires prompt intervention, sometimes temporary stenting of the ureters to relieve pressure on the kidneys while a surgical plan is made for the fibroid itself. Fibroid erosion into the bladder typically requires surgical removal of the fibroid along with repair of the bladder wall. Fistula repair is a separate surgical procedure, sometimes performed at the same time as fibroid removal.
For the much more common lower urinary tract symptoms caused by fibroids, such as frequency, urgency, and incontinence, the same systematic review that found roughly half of fibroid patients experience these symptoms also confirmed that both stress urinary incontinence and urgency urinary incontinence were significantly more common in women with fibroids compared to women without them.1PubMed Central. Lower Urinary Tract Symptoms in Uterine Myoma: A Systematic Review and Meta-Analysis These symptoms frequently improve after fibroid treatment, whether that involves myomectomy (removing the fibroid while preserving the uterus), hysterectomy, or other approaches. In some cases, medications that shrink fibroids can reduce urinary symptoms enough to avoid surgery.
Why Fibroid-Related Hematuria Gets Missed
One reason fibroid-related blood in the urine sometimes goes undiagnosed for a long time is compartmentalized medical care. A gynecologist managing your fibroids may not ask about urinary bleeding, while a urologist investigating hematuria may not think to evaluate the uterus. The pelvic organs are neighbors, and problems in one can masquerade as problems in another. This is especially true when fibroids are large and are compressing or directly invading urinary structures.
In the case of the 33-year-old woman with bilateral ureteral obstruction from a nearly 20-centimeter fibroid, the initial finding was incidental fullness felt during a routine exam, and the renal impairment was only discovered on subsequent evaluation.5PubMed Central. Bilateral Obstructive Uropathy From a Large Uterine Fibroid Causing Severe Renal Impairment: A Case Report The fibroid had been silently damaging her kidneys. Similarly, the woman with cyclical hematuria from a vesicouterine fistula went three years with her menstrual blood draining into her bladder before the fistula was found.
If you have large fibroids and develop any new urinary symptom, including blood in the urine, mention your fibroid history to whoever is evaluating you. Cross-specialty communication can shorten the diagnostic path considerably. And if you have very large fibroids, even without symptoms, periodic checks of kidney function (a simple blood test) and imaging of the urinary tract can catch obstruction before it causes lasting damage.