Medically reviewed by
Dr. Jacob White, MD, RPVI, Interventional Radiologist, Fibroid Specialist and Medical Director
Reviewed: October 2026
Uterine fibroids are non-cancerous growths that affect up to 80 percent of women in the United States by age 50, and while many fibroids cause no symptoms, larger or fast-growing fibroids can sometimes lead to a painful process called fibroid degeneration.[1] Fibroid degeneration happens when a fibroid outgrows its blood supply and its tissue starts to break down. The process can bring on sudden, sharp pelvic pain or build up more slowly, and it does not always mean a fibroid is going away for good. Knowing what is actually happening inside a degenerating fibroid can help you recognize the signs early and understand when it is time to see a specialist. Here is what every fibroid patient should know, from what triggers the degeneration process to how it is evaluated.
Quick facts
- Fibroids depend on a steady blood supply to survive, and tissue begins to die when that supply can no longer keep up with the fibroid’s size[1]
- Degeneration is grouped into several types based on how the tissue changes, including hyaline, cystic, calcific, myxoid, fatty, and red degeneration[1]
- Red degeneration, sometimes called necrobiosis, is the type most often associated with pregnancy[2]
What Is Fibroid Degeneration?
Fibroid degeneration is the process that occurs when a fibroid grows larger than the blood supply feeding it can support. Fibroids are made of living tissue, so they need a steady flow of oxygen and nutrients through nearby blood vessels to keep growing.[1] When a fibroid outpaces that blood supply, the cells at the center of the fibroid are cut off from nutrients and begin to die. This tissue breakdown is what doctors call degeneration.
Degeneration does not always look the same from one fibroid to the next. Depending on how the tissue breaks down, a fibroid may undergo hyaline degeneration, where normal tissue is replaced with a glassy material, calcific degeneration, where calcium deposits harden the tissue, or cystic degeneration, where fluid-filled pockets form inside the fibroid.[1] Understanding the different types of fibroids can also help explain why some fibroids are more prone to this process than others.
What Causes a Fibroid to Degenerate?
A fibroid most often degenerates after a period of rapid growth, when its size outpaces the blood vessels available to feed it.[1] Larger fibroids, and those that grow quickly, such as during pregnancy when hormone levels rise sharply, are more likely to reach this point.
Fibroid location can also play a role. Pedunculated fibroids, which grow attached to the uterus by a narrow stalk, are more prone to degeneration because the stalk can become twisted and cut off blood flow on its own.[2] A sudden drop in estrogen, which can happen around menopause, may also leave a fibroid without enough hormonal support to maintain its blood supply, triggering a similar breakdown.
Because fibroid behavior varies so widely between patients, there is no way to predict exactly which fibroids will degenerate and which will continue growing undisturbed. Fibroid size is one factor a specialist may consider when discussing your individual risk.
Symptoms of Fibroid Degeneration
The most common symptom of fibroid degeneration is sudden, sharp pelvic or abdominal pain, often centered over the fibroid itself.[2] The pain can feel different from typical period cramps and may come with noticeable swelling or tenderness in the area. Other symptoms can include:
- A low-grade fever, especially when degeneration happens during pregnancy
- Pain that lingers as a dull, chronic ache after the sharp pain eases
- Abnormal or heavier than usual bleeding, which should always be evaluated promptly
- Nausea or fatigue in some cases
Symptoms from a degenerating fibroid typically last anywhere from a few days to a few weeks.[2] Because a fibroid can shrink, stabilize, and then begin growing again, symptoms may ease for a while and return later if the fibroid regains enough blood supply to keep growing.
How Is Fibroid Degeneration Evaluated and Diagnosed?
Sudden pelvic pain should always be evaluated promptly, since the symptoms of fibroid degeneration can overlap with other conditions, including ovarian cysts or gastrointestinal issues.[1] A fibroid specialist typically starts with a physical exam and a review of your symptoms and medical history.
Imaging, most often an ultrasound or MRI, is the most reliable way to confirm fibroid degeneration and rule out other causes of pain.[1] Imaging can also show the size, location, and number of fibroids present, which helps guide any discussion about next steps. In some cases, your provider may order blood work to check for signs of infection or significant blood loss.
During the acute phase, care usually focuses on rest, hydration, and pain management while the fibroid stabilizes. Once the sharp pain subsides, a fibroid specialist can talk through options for addressing the underlying fibroid to help reduce the chance of another painful episode.
Fibroid Degeneration During Pregnancy
Fibroid degeneration can also happen during pregnancy, when rising hormone levels cause some fibroids to grow quickly. This type of degeneration is sometimes called necrobiosis and can cause sudden abdominal pain along with a low-grade fever.[2]
If you are pregnant and experience sudden or severe abdominal pain, contact your provider promptly so they can confirm the cause and monitor both you and your pregnancy. Most cases of degeneration during pregnancy are managed with rest and pain control, and symptoms typically improve within one to two weeks.
Addressing the Fibroid Behind Degeneration
Degeneration on its own is not a treatment. A fibroid that stops degenerating can still regain its blood supply and start growing again, which means symptoms can return.[1] For patients who want to address the fibroid directly rather than wait out repeated cycles of pain, Uterine Fibroid Embolization (UFE) is a minimally invasive, image-guided option.
During UFE, an interventional radiologist uses a catheter to deliver tiny particles into the blood vessels feeding the fibroid, blocking its blood supply directly.[3] Because UFE targets the fibroid’s blood supply rather than waiting for a natural hormonal shift, it may help some patients avoid repeated cycles of degeneration, pain, and regrowth. UFE preserves the uterus and is performed on an outpatient basis.
Degeneration is also different from fibroid sloughing, which happens when dead fibroid tissue detaches and passes out of the body rather than staying in place. A fibroid specialist can help explain which process may be happening and what it means for your care.
Wondering if UFE is available near you? Find the location closest to you.
Treatment option: UFE
You Do Not Have to Wait Out the Cycle
Fibroid degeneration can bring temporary relief from symptoms, but it does not guarantee the fibroid is gone for good, and pain can return if the fibroid begins growing again.
Uterine Fibroid Embolization is a minimally invasive, outpatient option that addresses a fibroid’s blood supply directly. A fibroid specialist can help you understand whether UFE may be right for your situation.
FAQs About Fibroid Degeneration
- NCBI Bookshelf, StatPearls Publishing, “Uterine Leiomyomata,” ncbi.nlm.nih.gov/books/NBK546680/
- MSD Manuals Professional Edition, “Uterine Fibroids,” msdmanuals.com/professional/gynecology-and-obstetrics/uterine-fibroids
- Society of Interventional Radiology, “Uterine Fibroid Embolization,” sirweb.org/patients/uterine-fibroids/
Medical Disclaimer: This article provides educational information about fibroid degeneration and related treatment options. It is not a diagnosis or medical advice. Only a qualified fibroid specialist can determine whether you have a degenerating fibroid or recommend appropriate treatment. If you have sudden pelvic pain, heavy bleeding, or other symptoms, consult a healthcare provider or contact USA Fibroid Centers for an evaluation.