Fibroids and Symptoms Of Adenomyosis: Why It Happens and What Helps

Heavy periods, pelvic pain, and a persistently bloated or pressure-filled feeling can upend your routine and raise questions about what’s going on with your uterus. Two common culprits—uterine fibroids and adenomyosis—can cause similar symptoms, often overlap, and sometimes occur together. Understanding how they differ, why they happen, and what truly helps can empower you to get the right diagnosis and care.

What Are Fibroids?

Uterine fibroids (leiomyomas) are noncancerous growths of the uterine muscle. They’re extremely common—most women will develop them at some point, though not all have symptoms. Fibroids can vary in size from a seed to a grapefruit and grow in different locations: within the uterine wall (intramural), bulging into the cavity (submucosal), or projecting outward (subserosal).

Common fibroid symptoms include:

• Heavy menstrual bleeding (with clots) and prolonged periods
• Pelvic pressure or fullness; abdominal enlargement
• Painful periods, pelvic pain, or back pain
• Frequent urination or constipation (from pressure on bladder/bowel)
• Fatigue from iron-deficiency anemia

What Is Adenomyosis?

Adenomyosis occurs when tissue similar to the uterine lining (endometrium) grows into the muscular wall of the uterus (myometrium). This can make the uterus enlarged and tender and may intensify cramping and bleeding. Unlike endometriosis (which involves similar tissue outside the uterus), adenomyosis is within the uterine muscle itself.

Common adenomyosis symptoms include:

• Heavy, prolonged menstrual bleeding
• Severe cramps (dysmenorrhea) and chronic pelvic pain
• Pain with intercourse
• Enlarged, often tender uterus

Why Do They Happen?

Both conditions are hormonally responsive and tend to occur during the reproductive years, improving after menopause for many.

Fibroids: Contributing factors

• Hormones: Estrogen and progesterone promote fibroid growth.
• Genetics & family history: Fibroids often run in families.
• Age and ancestry: More common and often more severe in people in their 30s–50s; higher prevalence and symptom burden among Black women.
• Other factors: Early menstruation, obesity, and vitamin D deficiency are associated in some studies.

Adenomyosis: Contributing factors

• Hormone sensitivity: Estrogen appears to promote the ectopic endometrial tissue within the muscle.
• Uterine injury or inflammation: Prior childbirth, cesarean section, or uterine surgery may be associated, though adenomyosis also occurs without these.
• Age: Most often diagnosed in people 35–50, but it can affect younger individuals too.

How Fibroids and Adenomyosis Differ—and Overlap

• Bleeding: Both can cause heavy or prolonged periods. Adenomyosis often brings more intense cramping with bleeding.
• Pain: Adenomyosis tends to cause diffuse, crampy pain and uterine tenderness; fibroid pain is more variable and can be related to bulk or degeneration.
• Bulk symptoms: Fibroids more commonly cause pressure effects (urinary frequency, constipation, visible abdominal enlargement).
• Fertility: Submucosal fibroids can affect fertility and miscarriage risk; adenomyosis may also be associated with infertility and adverse pregnancy outcomes in some cases.

Getting the Right Diagnosis

Your clinician will start with a detailed history and pelvic exam, then typically order imaging:

• Transvaginal ultrasound: First-line for identifying fibroids and features suggestive of adenomyosis (a globular uterus, heterogeneous myometrium).
• MRI: Helpful when ultrasound is inconclusive or when planning procedures; better at distinguishing adenomyosis from fibroids.
• Labs: A complete blood count (CBC) checks for anemia from heavy bleeding; iron studies may be warranted.
• Endometrial sampling: May be recommended to rule out other causes of abnormal bleeding, especially after age 45 or with risk factors.

Definitive diagnosis of adenomyosis historically required pathology after hysterectomy, but modern imaging often provides high-confidence, noninvasive diagnosis.

What Helps: Evidence-Based Options

Self-care and supportive measures

• Track your cycle and symptoms: Note bleeding volume and pain to guide treatment decisions.
• NSAIDs: Ibuprofen or naproxen started at the onset of menses can reduce cramps and modestly reduce bleeding. Ask your clinician about safe dosing.
• Iron support: If you have heavy bleeding, discuss checking ferritin and supplementing iron to prevent or treat anemia.
• Heat, gentle exercise, stress reduction: Can help pelvic pain and cramps.

Medications

• Hormonal contraception: Combined pills, patch, or ring; or progestin-only methods can lighten periods and reduce cramps for both fibroids and adenomyosis. The levonorgestrel-releasing IUD is particularly effective for heavy bleeding and pain, including with adenomyosis.
• Tranexamic acid: A nonhormonal option taken only during menses to reduce heavy bleeding due to fibroids. Important: Tranexamic acid should not be used with estrogen-containing birth control because of clot risk; review your history with your clinician.
• GnRH agonists/antagonists: These reduce estrogen levels to shrink fibroids and decrease bleeding. FDA-approved options for heavy menstrual bleeding due to fibroids include elagolix/estradiol/norethindrone (Oriahnn) and relugolix/estradiol/norethindrone (Myfembree), typically used with “add-back” hormones to protect bones and limit menopausal side effects. Use is generally time-limited due to bone mineral density concerns.
• Progestins for adenomyosis: Oral progestins or the levonorgestrel IUD often improve pain and bleeding. GnRH analogs may be used short term.

Uterine-sparing procedures

• Myomectomy: Surgical removal of fibroids while preserving the uterus; can be hysteroscopic (inside the cavity), laparoscopic, or open. Often preferred when fertility is a priority, especially for submucosal fibroids.
• Uterine artery embolization (UAE): Minimally invasive procedure that shrinks fibroids by blocking blood supply. Many experience reduced bleeding and pressure; recovery is typically shorter than surgery. It can also help adenomyosis symptoms for some, though responses vary.
• Radiofrequency ablation (RFA): Laparoscopic or transcervical energy to shrink fibroids with relatively quick recovery.
• MRI-guided focused ultrasound (MRgFUS): Noninvasive thermal ablation for select fibroids.

Definitive surgery

• Hysterectomy: Removal of the uterus is a highly effective, definitive treatment for both fibroids and adenomyosis when other options fail or are not desired. It ends menstrual bleeding and eliminates uterine pain sources but is not appropriate for those who wish to carry a pregnancy.

Choosing the Right Path

The best option depends on your symptoms, fibroid size and location, whether adenomyosis is present, your overall health, and your goals around fertility and recovery time. A gynecologist can help you weigh trade-offs—such as recurrence risk after myomectomy, amenorrhea rates with IUDs, or the bone health considerations of GnRH-based therapies.

When to Seek Care Promptly

• Soaking through a pad or tampon every 1–2 hours or passing large clots
• Dizziness, shortness of breath, or signs of anemia
• Severe pelvic pain, fever, or sudden worsening symptoms
• Bleeding between periods or after sex

These symptoms warrant timely evaluation to rule out other conditions and to prevent complications like severe anemia.

Trusted Sources and Further Reading

• American College of Obstetricians and Gynecologists (ACOG): Uterine Fibroids – https://www.acog.org/womens-health/faqs/uterine-fibroids
• ACOG: Adenomyosis – https://www.acog.org/womens-health/faqs/adenomyosis
• NIH MedlinePlus: Adenomyosis – https://medlineplus.gov/adenomyosis.html
• NIH/NICHD: Uterine Fibroids Overview – https://www.nichd.nih.gov/health/topics/uterine/conditioninfo/fibroids
• FDA: Tranexamic Acid (Lysteda) Safety Information – https://www.fda.gov/drugs/postmarket-drug-safety-information-patients-and-providers/lysteda-tranexamic-acid
• FDA: Myfembree (relugolix/estradiol/norethindrone) and Oriahnn (elagolix/estradiol/norethindrone) Prescribing Information – https://www.fda.gov/drugs
• U.S. Office on Women’s Health: Uterine Fibroids – https://www.womenshealth.gov/a-z-topics/uterine-fibroids

If heavy bleeding or pelvic pain is affecting your life, you’re not alone—and you have options. Partnering with a clinician who listens and tailors care to your goals can make a meaningful difference.