Uterine fibroids are almost never a direct cause of death, but they can trigger a chain of complications that becomes life-threatening if untreated. A large prospective cohort study found that fibroids were not associated with increased all-cause premature mortality, yet they were linked to more than double the risk of dying from gynecological cancers, likely because a small number of apparent fibroids turn out to be malignant tumors in disguise. The real dangers lie not in the fibroid itself but in what it can do to surrounding organs, blood supply, and pregnancy when it grows unchecked or goes unmonitored.
What the Mortality Data Actually Shows
The most direct evidence comes from a prospective cohort study that tracked women with ultrasound- or hysterectomy-confirmed fibroids over time. The study found no meaningful increase in all-cause premature death, with a hazard ratio of 1.03, essentially no different from women without fibroids. Where the numbers shifted was in cause-specific mortality: women with fibroids had roughly 2.3 times the risk of dying from malignant tumors of the gynecological organs.1PubMed Central. Endometriosis and uterine fibroids and risk of premature mortality: prospective cohort study That elevated risk likely reflects cases where what was thought to be a benign fibroid was actually a uterine sarcoma, a point we’ll return to later. The takeaway is reassuring but incomplete: having fibroids does not shorten your life on average, but the rare severe complications deserve attention because they are the ones that can become emergencies.
Severe Anemia and Heart Failure from Fibroid Bleeding
Heavy menstrual bleeding is the most common fibroid symptom, and most women with it manage the problem without hospitalization. But when bleeding goes unaddressed for months or years, anemia can become severe enough to damage the heart. One published case report described a woman whose hemoglobin dropped to 1.4 g/dL from fibroid-induced hemorrhage, a fraction of the normal range. She arrived hemodynamically unstable with metabolic acidosis and developed acute left ventricular dysfunction afterward, with her heart’s pumping capacity falling to an ejection fraction of roughly 28 percent.2PubMed Central. Severe Anemia (1.4 g/dL) Due to Uterine Fibroid Bleeding With Reversible Myocardial Dysfunction: A Case Report
The encouraging detail in that case is that the cardiomyopathy was fully reversible once her anemia was corrected. But it illustrates how fibroids can become indirectly lethal: the fibroid bleeds, the anemia worsens slowly enough that the body compensates until it can’t, and then the heart fails. This progression is most dangerous in women who delay care, lack access to it, or whose symptoms are dismissed as normal heavy periods.
Blood Clots from Pelvic Vein Compression
Large fibroids sitting in the pelvis can compress the veins that drain the legs, creating the same kind of stagnant blood flow that causes deep vein thrombosis on a long airplane flight. A case series of seven women documented this association, with pelvic vein compression by fibroids directly observed on imaging in five of the cases. The patients developed deep vein thrombosis and, in some cases, pulmonary embolism.3PubMed Central. Case series of seven women with uterine fibroids associated with venous thromboembolism and chronic thromboembolic disease
In one case, a woman with a known history of leiomyoma presented with an acute clot in her leg and a mass in her right pulmonary artery. MRI confirmed that a large fibroid was compressing both common iliac veins, and the resulting stagnant blood flow was the most likely cause of the clot that traveled to her lungs.4PubMed Central. Acute pulmonary embolism caused by enlarged uterine leiomyoma: A rare presentation Pulmonary embolism can be fatal if the clot is large enough. This complication is uncommon, but it’s the kind of thing that gets missed when clinicians aren’t thinking about fibroids as a source of vascular problems. If you have large fibroids and develop sudden leg swelling or unexplained shortness of breath, it’s worth flagging your fibroid history to whoever is treating you.
Torsion and Bowel Obstruction
Not all fibroids grow within the uterine wall. Some, called pedunculated fibroids, hang off the outside of the uterus on a stalk. If that stalk twists, the fibroid’s blood supply gets cut off. The result is torsion, which causes sudden, severe abdominal pain and can lead to tissue death if it isn’t caught quickly. One case report described a fibroid that had twisted 270 degrees on its stalk, with early gangrenous changes already visible at surgery.5PubMed Central. Torsion of a Pedunculated Subserosal Leiomyoma: A Rare Cause of Acute Abdominal Pain A long, thin stalk and a larger fibroid mass are risk factors for this happening.
Without surgery, torsion can progress to ischemic gangrene and peritonitis, an infection of the abdominal lining that can become fatal.6International Journal of Surgery Case Reports. Uterine leiomyoma torsion: A rare cause of acute abdominal pain The condition requires emergency surgery, and the good news is that once the torsed fibroid is removed, recovery is typically straightforward. The danger lies in misdiagnosis: torsion of a pedunculated fibroid can mimic ovarian torsion, appendicitis, or other causes of acute abdominal pain.7PubMed Central. Imaging findings of a torsed pedunculated uterine leiomyoma: A case report
Fibroids can also cause bowel obstruction in rare cases. One report described a 72-year-old postmenopausal woman who presented with abdominal pain, vomiting, and inability to pass stool. Imaging revealed that a large, calcified exophytic fibroid was compressing her cecum and causing a partial volvulus, requiring open surgery to resolve.8Cureus. Large Bowel Obstruction From a Calcified Uterine Fibroid: A Rare Cause of Extrinsic Compression This is a reminder that fibroids don’t stop being a problem after menopause. While they tend to shrink once estrogen drops, large or calcified fibroids can persist and cause mechanical complications decades later.
Infected Fibroids and Sepsis
A pyomyoma is a fibroid that has become infected, essentially an abscess inside or around the fibroid tissue. It is rare, but when it happens, the consequences can be severe. A classic triad of symptoms includes abdominal pain, signs of sepsis without an obvious source, and a known history of fibroids.9PubMed Central. Pyomyoma as a Rare Source of Postpartum Sepsis In most reported cases, a total hysterectomy has been required to control the infection and prevent death.
Pyomyoma can occur spontaneously, but it also shows up as a complication after procedures like uterine artery embolization (UAE), where the deliberate cutting off of blood flow to the fibroid creates dead tissue that can become a breeding ground for bacteria. One case report described a patient who developed septic shock from a necrotic fibroid eight weeks after UAE, requiring emergency hysterectomy.10PubMed. Necrotic leiomyoma and gram-negative sepsis eight weeks after uterine artery embolization Another case involved a young woman with no prior pregnancies who presented with a surgical abdomen, fever, and low blood pressure; she was found to have a ruptured pyomyoma that had spilled infected material into her abdominal cavity.11PubMed Central. Spontaneous Ruptured Pyomyoma in a Nulligravid Female: A Case Report and Review of the Literature Both scenarios can become life-threatening rapidly.
The Leiomyosarcoma Problem
Perhaps the most unsettling complication of fibroids isn’t really a complication at all. It’s the possibility that what looks like a fibroid is actually a leiomyosarcoma, a rare but aggressive uterine cancer. On imaging and during clinical examination, the two can look strikingly similar, and reliably telling them apart before surgery remains a genuine challenge.12PubMed. How to differentiate uterine leiomyosarcoma from leiomyoma with imaging Because a suspected fibroid is often managed conservatively or treated with minimally invasive approaches, misdiagnosing a sarcoma as a benign fibroid can delay treatment and increase the chance of a bad outcome.
How often does this happen? The FDA initially estimated the rate of occult leiomyosarcoma at about 1 in 500 surgeries for presumed fibroids. More recent analyses have produced lower figures, with one meta-analysis of prospective studies estimating about 1 in 8,300 surgeries, and another including both prospective and retrospective data arriving at roughly 1 in 1,400.13PubMed. The prevalence of occult leiomyosarcoma in women undergoing presumed fibroid surgery and outcomes after morcellation Even at the lower end, this is not zero, and it matters because of what happens during surgery. Morcellation, a technique where a large fibroid is cut into smaller pieces inside the body to remove it through a small incision, can spread an undiagnosed sarcoma throughout the abdomen. One case report described a 48-year-old woman who underwent laparoscopic hysterectomy with vaginal extraction for what was thought to be a fibroid. Four months later, she developed extensive pelvic and abdominal spread of uterine sarcoma.14PubMed Central. Intraperitoneal spread in uterine sarcoma following unprotected laparoscopic transvaginal uterine morcellation: a case report and literature review
MRI is currently the best imaging tool for raising suspicion before surgery. Radiologists look for a cluster of features, including irregular borders, certain enhancement patterns, signs of hemorrhage, and restricted diffusion, that together increase the likelihood that a mass is a sarcoma rather than a benign fibroid.15PubMed Central. Differentiating uterine sarcoma from leiomyoma: BET1T2ER Check! No imaging technique can currently give a definitive answer, but combining MRI features with clinical context significantly improves accuracy. If your doctor is recommending fibroid surgery, asking about MRI evaluation and the risks of morcellation is reasonable.
Fibroids During Pregnancy
Fibroids and pregnancy interact in ways that can escalate from uncomfortable to dangerous. A recent retrospective cohort study found that women with fibroids had nearly five times the odds of postpartum hemorrhage compared to women without them, and about a 52 percent increase in the odds of needing a cesarean section.16PubMed Central. Association of uterine fibroids with adverse pregnancy outcomes: a retrospective cohort study Postpartum hemorrhage alone is one of the leading causes of maternal death worldwide, so the combination of fibroids and pregnancy is one that obstetricians take seriously.
Fibroids can also undergo red degeneration during pregnancy, a process where the fibroid outgrows its blood supply and the tissue inside begins to break down. This produces sudden, intense abdominal pain that can mimic more dangerous conditions. Red degeneration typically responds to conservative management with pain control and monitoring, but the challenge is distinguishing it from torsion of a pedunculated fibroid, which requires emergency surgery.17PubMed. Red degeneration of fibroid presenting with abdominal pain in pregnancy Getting the diagnosis wrong in either direction has consequences: unnecessary surgery during pregnancy carries its own risks, while delaying surgery for true torsion allows tissue death to progress.
When Treatment Itself Carries Risk
The treatments for fibroids are generally safe, but they are not risk-free, and the complication profiles differ meaningfully depending on the approach. In a comparison of surgical options, abdominal myomectomy (open surgery to remove fibroids) had the highest complication rate at about 20 percent, followed by abdominal hysterectomy at roughly 14 percent. Laparoscopic procedures fared much better: laparoscopic hysterectomy had a complication rate around 8 percent, and laparoscopic myomectomy came in lowest at about 5.5 percent.18American Journal of Obstetrics & Gynecology. Peri-menopausal women undergoing myomectomy versus hysterectomy for the treatment of uterine leiomyoma
Uterine artery embolization, a nonsurgical option where the blood supply to fibroids is deliberately blocked, carries its own set of serious but uncommon complications, including pulmonary embolism, uterine necrosis, sepsis, and in rare cases, death.19PubMed Central. Complications of uterine fibroid embolization Two case reports reinforced that UAE can sometimes lead to life-threatening complications requiring emergency hysterectomy, essentially negating the organ-sparing advantage that made the procedure attractive in the first place.20PubMed. Serious complications of uterine artery embolization for conservative treatment of fibroids None of this means UAE should be avoided; for many women it works well and recovers faster than surgery. But the decision should involve an honest conversation about what can go wrong, particularly the small risk of post-embolization infection.
Kidney Damage from Compression
Fibroids that grow large enough can press on structures beyond the uterus. The ureters, the tubes connecting your kidneys to your bladder, run through the pelvis and are vulnerable to compression by a bulky fibroid uterus. When a ureter gets squeezed, urine backs up into the kidney, a condition called hydronephrosis, which can damage the kidney if it persists. One case report documented this in a kidney transplant recipient, where a leiomyomatous uterus was compressing the transplant ureter and causing hydronephrosis in the patient’s only functioning kidney.21PubMed Central. Uterine artery embolization for fibroid-induced hydronephrosis in a renal transplant recipient That scenario is extreme, but even in women with two healthy kidneys, prolonged ureteral compression from fibroids can silently reduce kidney function before symptoms appear.
Who Is Hit Hardest
Fibroids are not distributed equally across the population, and neither are their consequences. A systematic review found that fibroid prevalence is consistently higher in Black women than in White women, with the gap varying by population and how fibroids are defined.22PubMed Central. Racial disparities in uterine fibroids and endometriosis: a systematic review and application of social, structural, and political context The disparity goes beyond just having fibroids more often. Black women tend to develop them earlier, have larger and more numerous fibroids at diagnosis, and experience worse clinical and surgical outcomes than White women with the same condition. The review pointed to a range of social, structural, and political factors across the life course that contribute to these differences, from environmental exposures to access to timely care.
This is directly relevant to the question of whether fibroids can kill. Many of the dangerous complications described in this article, from severe anemia progressing to heart failure, to large fibroids compressing pelvic veins, to delayed diagnosis of occult sarcoma, are more likely when fibroids are larger at the time of treatment, when treatment is delayed, or when symptoms are minimized. If the healthcare system consistently provides less prompt and less effective care to one group of women, that group is more likely to encounter the severe end of the complication spectrum.
Rare Endocrine Effects
Fibroids occasionally do something biochemically strange: they produce erythropoietin, the hormone that tells your bone marrow to make more red blood cells. The result is a condition called myomatous erythrocytosis syndrome, where the fibroid drives the body into an abnormally high red blood cell count.23PubMed Central. Secondary Erythrocytosis Associated with Uterine Myoma Is Rare but Should Be of Concern This is essentially the opposite of the anemia that most fibroid patients deal with. Too many red blood cells thicken the blood and raise the risk of clots and stroke.
The condition is diagnosed by its triad: erythrocytosis, the presence of fibroids, and normalization of blood counts after the fibroids are surgically removed. In one reported case, a 44-year-old woman presented with a large uterine mass and elevated hemoglobin. Her serum erythropoietin was elevated, and after hysterectomy, the hemoglobin returned to normal. The removed tissue was confirmed to be a benign leiomyoma.24PubMed Central. Erythropoietin-Secreting uterine leiomyoma presenting with secondary erythrocytosis: A case report This syndrome is vanishingly rare, but it’s a useful reminder that fibroids are hormonally active tissue, not just inert lumps of muscle, and occasionally they produce substances that affect the rest of the body in unexpected ways.25PubMed Central. Rapidly developing myomatous erythrocytosis syndrome: a case report
Symptoms That Should Send You to an Emergency Room
Most women with fibroids will never face any of the emergencies described above. But knowing which symptoms warrant urgent attention can be the difference between a manageable situation and a dangerous one. Sudden, severe abdominal pain, especially if you know you have pedunculated fibroids, could signal torsion. Unexplained fever combined with abdominal pain and a fibroid history raises the possibility of pyomyoma. Progressive shortness of breath or sudden leg swelling in someone with large pelvic fibroids could point to a blood clot. And chronic heavy bleeding that leaves you dizzy, short of breath on exertion, or with a racing heart at rest is not something to tough out; it means your body is running out of red blood cells faster than it can replace them.
None of these symptoms are specific to fibroids alone, which is exactly the problem. They overlap with dozens of other conditions, and fibroids are sometimes the last thing anyone considers as the cause. If you already know you have fibroids and you develop any of these symptoms, mentioning that history to your emergency provider gives them a head start on figuring out what’s going on.