A degenerating fibroid is a fibroid that has outgrown its blood supply, so part of its tissue starts to break down. It is not cancer, and it does not mean the fibroid is turning into cancer. Degeneration may simply be noted on an imaging report, but it can also cause pelvic pain, sometimes sudden and severe. Because that kind of pain can also come from emergencies that have nothing to do with fibroids, severe pelvic pain should be checked the same day. This guide explains what degeneration is, the symptoms, and when to go to the emergency room.
What "degenerating" means
Fibroids are noncancerous growths of the muscle wall of the uterus. Like any tissue, they need blood flow. A widely cited 1999 review in the journal Radiographics explains that as fibroids enlarge, they may outgrow their blood supply, and this leads to different types of degeneration:
- Hyaline degeneration, the most common type, according to a companion review from the same year.
- Cystic degeneration, in which fluid-filled spaces form inside the fibroid.
- Myxoid degeneration, another change in the fibroid's tissue.
- Calcification, in which calcium deposits form in the fibroid.
- Red (carneous) degeneration, in which bleeding occurs inside the fibroid. This type is most often linked with pregnancy.
The word "degeneration" sounds worrying, but it describes what is happening inside a benign growth. The authors of the companion review describe fibroids as exclusively benign.
Symptoms of a degenerating fibroid
ACOG, the national organization of obstetrician-gynecologists, notes that fibroids that grow rapidly, or those that start breaking down, may cause pain. When degeneration does cause symptoms, people commonly describe:
- Pain in the lower abdomen or pelvis, which may be sudden and sharp or a steady ache
- Tenderness over the area of the fibroid
- Sometimes a low fever or feeling generally unwell
Many fibroids, including some with degeneration on imaging, cause no pain at all. If you already have other fibroid symptoms, such as heavy periods or pressure, our overview of fibroid symptoms covers the common ones.
Degeneration during pregnancy
Red degeneration is the type most linked with pregnancy. A 2026 review from the International Federation of Gynecology and Obstetrics (FIGO) reports that it is the most common fibroid complication in pregnancy, and says it can occur in 8% of women in that setting. The same review stresses that most pregnancies with fibroids are uncomplicated.
A review of acute fibroid complications published in 2009 notes that the fibroid itself is managed conservatively during pregnancy, with definitive treatment postponed until after delivery. If you are pregnant and have pelvic pain, contact your obstetrician or go to labor and delivery or the emergency room. Do not assume the pain is your fibroid.
Questions about your treatment options? Dr. Fox can help.
Book a ConsultationThis article is part of our Fibroid Treatment Guide.
A twisting fibroid is different
Some fibroids grow on a stalk from the outside of the uterus. These are called pedunculated fibroids. ACOG notes that fibroids on a stalk may twist and can cause pain, nausea or fever. A twisted fibroid can lose its blood supply suddenly. The 2009 review describes this as one of the acute fibroid complications that usually present as an acute abdomen and may need urgent surgery. If you have been told you have a fibroid on a stalk, our article on pedunculated fibroids explains the options.
When to go to the emergency room
Acute fibroid complications are uncommon. The 2009 review calls it "remarkable how very rarely" fibroids cause them. But the same review lists other conditions that can look similar, including a twisted ovary, a ruptured ectopic pregnancy and a bleeding ovarian cyst. Some of these are emergencies. Go to the emergency room or call 911 if you have:
- Sudden, severe pain in the pelvis or abdomen
- Pelvic pain with a fever or shaking chills
- Pelvic pain with nausea or vomiting that keeps you from drinking fluids
- Dizziness, fainting, a racing heartbeat, or very heavy bleeding
- Pelvic pain and a chance you could be pregnant
- Pain while pregnant, along with bleeding, fluid leaking or contractions
Call your gynecologist within a day or two for pelvic pain that is new, is getting worse, or keeps coming back, even if it is not severe.
| Situation | Suggested action |
|---|---|
| Imaging report mentions degeneration; no pain | Discuss at your next routine visit |
| Mild, steady ache you can manage | Call your gynecologist for advice and an exam |
| Pain that keeps coming back | Book a visit to look at the cause and treatment options |
| Sudden severe pain, fever, fainting, heavy bleeding | Emergency room or 911 |
| Any pelvic pain in pregnancy | Call your obstetrician or go to labor and delivery |
How a degenerating fibroid is diagnosed
Diagnosis starts with your history and an exam, often with a pregnancy test and blood work. An ultrasound is usually the first scan. Degenerating fibroids can look different from typical fibroids, and the Radiographics review notes that degenerated fibroids have variable appearances on MRI. An MRI may be used when the picture is unclear or when other causes, such as an ovarian mass or adenomyosis, need to be ruled out. Our guide to fibroid diagnosis with ultrasound and MRI explains what each test shows.
How it is managed
We did not find a major guideline that sets out one standard treatment for degenerating fibroids outside pregnancy, so management depends on your situation and your doctor's assessment. In general:
- Pain relief. The Office on Women's Health notes that over-the-counter drugs such as ibuprofen or acetaminophen can be used for mild fibroid pain. Ask your doctor which medicine is safe for you, especially if you are pregnant, have kidney or stomach problems, or take blood thinners.
- Follow-up. Your doctor may want to see you again or repeat imaging to confirm the cause of the pain.
- Treating the fibroids. If pain keeps returning, or if the fibroids also cause heavy bleeding or pressure, it may be time to talk about treatment. Options range from medication to myomectomy, hysterectomy and uterine fibroid embolization (UFE). Our fibroid treatment guide compares them.
Degeneration and fibroid embolization
UFE works by deliberately cutting off the blood supply to fibroids so that they shrink. The pain, low fever and tiredness some people feel in the first few days afterward are called post-embolization syndrome. This is an expected part of recovery after a planned procedure, and it is different from the unexpected pain of spontaneous degeneration. Your care team will give you specific instructions about which symptoms after UFE need a call.
Frequently Asked Questions
What does a degenerating fibroid feel like?
When it causes symptoms, it is usually pain in the lower abdomen or pelvis, sometimes sudden and sharp, sometimes a steady ache, occasionally with a low fever. Many degenerating fibroids cause no pain.
Is a degenerating fibroid dangerous?
Degeneration happens in benign fibroids and is not cancer. The concern is that severe pelvic pain can also come from emergencies such as a twisted ovary or an ectopic pregnancy, so severe pain needs to be checked the same day.
Does a degenerating fibroid go away on its own?
The tissue changes do not reverse, but symptoms are often managed without surgery. If pain keeps returning, or the fibroid causes other symptoms, discuss treatment options with your doctor.
Can a fibroid degenerate during pregnancy?
Yes. Red degeneration is the most common fibroid complication in pregnancy, which a 2026 FIGO review says can occur in 8% of women in that setting. It is usually managed conservatively until after delivery.
Is pain after UFE the same as a degenerating fibroid?
Not exactly. After UFE, cramping and low fever in the first days are an expected reaction called post-embolization syndrome. Follow your care team's instructions on which symptoms need a call.
Keep Reading
- Uterine Fibroid Embolization (UFE) in New York City
- Pedunculated Fibroids and UFE: Safety, Stalk Width and Results
- Post-Embolization Syndrome After UFE: What Is Normal and When to Call
- Fibroid Diagnosis: Ultrasound vs MRI
- Fibroid Symptoms: 9 Signs to Know
- Fibroid Treatment Guide: every option, compared
Sources
- Murase et al., Radiographics, 1999 — Uterine leiomyomas: histopathologic features, MR imaging findings, differential diagnosis, and treatment
- Ueda et al., Radiographics, 1999 — Unusual appearances of uterine leiomyomas: MR imaging findings and histopathologic backgrounds
- Gupta and Manyonda, Best Pract Res Clin Obstet Gynaecol, 2009 — Acute complications of fibroids
- Ramasauskaite et al. (FIGO), Int J Gynaecol Obstet, 2026 — Fibroids and pregnancy
- American College of Obstetricians and Gynecologists — Uterine Fibroids (patient FAQ, last reviewed December 2025)
- Office on Women's Health, US Department of Health and Human Services — Uterine fibroids (updated February 2025)
- van Overhagen and Reekers, Cardiovasc Intervent Radiol, 2015 — CIRSE standards of practice: uterine artery embolization for symptomatic leiomyomata
Medically reviewed by David Fox, MD, FACS, RPVI. This article is general information, not a substitute for a medical evaluation.
Living with heavy periods, pelvic pressure or other fibroid symptoms? Schedule a consultation with Dr. David Fox at Fox Vein & Vascular in Manhattan to find out whether uterine fibroid embolization is right for you. Call (212) 362-3470 or request a UFE consultation online.
