Irregular Periods and Fibroids: What to Know

Irregular or heavy periods can disrupt daily life, sap your energy, and raise serious questions about your health. One common cause is uterine fibroids—noncancerous growths in or on the uterus. Understanding how fibroids affect menstrual cycles, how they’re diagnosed, and the full range of treatment options can help you make confident, informed decisions.

What are uterine fibroids?

Uterine fibroids (leiomyomas) are benign tumors made of muscle and fibrous tissue that grow in the uterine wall. They’re extremely common; by age 50, up to 70–80% of women will have fibroids, though not all will have symptoms. Their impact depends on size, number, and—most importantly—location. Fibroids can be:

• Submucosal (bulging into the uterine cavity)
• Intramural (within the uterine wall)
• Subserosal (on the outer surface of the uterus)

Submucosal and some intramural fibroids are most likely to cause period problems because they distort the uterine lining and blood flow.

How fibroids cause irregular or heavy periods

Fibroids can change the normal structure and function of the uterus in ways that alter bleeding:

• More lining to shed: Fibroids can increase the surface area of the uterine lining, leading to heavier, longer periods.
• Disrupted uterine contractions: The uterus may not contract effectively to stop bleeding.
• Fragile blood vessels: Fibroids can stimulate new, fragile vessels that bleed easily.
• Inflammation and hormonal effects: Local changes in hormones and inflammatory signals can prolong bleeding.

Common menstrual symptoms include heavy menstrual bleeding (soaking pads or tampons frequently, passing clots), periods that last more than 7 days, bleeding between periods, or cycles that come too often. Over time, heavy bleeding can cause iron-deficiency anemia—leading to fatigue, shortness of breath, headaches, and dizziness.

Don’t overlook other causes of irregular periods

Fibroids are not the only reason for cycle changes. Your clinician will consider other causes, including pregnancy, thyroid disorders, bleeding disorders, perimenopause, polycystic ovary syndrome (PCOS), medications (e.g., anticoagulants), uterine polyps, and endometrial hyperplasia. A thorough evaluation rules out these conditions and tailors treatment.

When to seek care—urgent vs. routine

• Call your clinician promptly if you have bleeding longer than 7 days, bleeding between periods, cycles closer than every 21 days, significant pelvic pain or pressure, trouble conceiving, or symptoms of anemia.
• Seek urgent care if you’re soaking through a pad or tampon every hour for more than 2 hours, feel lightheaded or faint, or have severe pelvic pain.

How fibroids are diagnosed

Your visit typically includes a medical history, pelvic exam, and one or more of the following tests:

• Pelvic ultrasound (often transvaginal): First-line imaging to identify fibroids and estimate size and location.
• Saline infusion sonohysterography (SIS): Saline is infused into the uterus during ultrasound to better outline submucosal fibroids.
• MRI: Provides detailed mapping, useful when planning procedures like myomectomy or uterine artery embolization.
• Hysteroscopy: A thin camera is inserted into the uterus to directly visualize and potentially remove submucosal fibroids.
• Lab tests: Pregnancy test, complete blood count (CBC), and iron studies to assess for anemia; additional tests as indicated.
• Endometrial biopsy: May be recommended to rule out other causes of abnormal bleeding, especially in patients over 45 or with risk factors.

Treatment options: from lifestyle to definitive care

The best approach depends on symptoms, fibroid size and location, your age, and whether you want to preserve fertility. Many therapies control bleeding effectively, and some shrink fibroids.

Watchful waiting and supportive care

• Observation: If fibroids are small and symptoms are mild, periodic monitoring may be all you need.
• Iron and nutrition: Treat iron-deficiency anemia with iron supplements (as advised by your clinician) and iron-rich foods; vitamin C can enhance absorption.
• NSAIDs: Nonsteroidal anti-inflammatory drugs (e.g., ibuprofen) can reduce menstrual flow and cramping for some people.

Medications that reduce bleeding

• Tranexamic acid: A non-hormonal option taken only during menses; reduces heavy menstrual bleeding.
• Hormonal contraception: Combined estrogen-progestin pills, patches, or rings and progestin-only methods can lighten periods and regulate cycles.
• Levonorgestrel-releasing IUD: Often markedly reduces bleeding and pain; also provides contraception. It may be less effective if the cavity is significantly distorted by submucosal fibroids.
• GnRH agonists and antagonists: Temporarily suppress estrogen to reduce bleeding and shrink fibroids. FDA-approved oral combinations (e.g., elagolix- or relugolix-based regimens with “add-back” therapy) can control heavy menstrual bleeding associated with fibroids. These are typically used for limited durations due to potential effects on bone density and other side effects; your clinician will monitor and advise.

Procedures that target fibroids

• Hysteroscopic myomectomy: Removes submucosal fibroids through the cervix, preserving the uterus and often improving bleeding significantly.
• Laparoscopic or open myomectomy: Removes fibroids from the uterine wall or surface; preserves fertility but may have a risk of fibroid recurrence.
• Uterine artery embolization (UAE): A minimally invasive radiology procedure that shrinks fibroids by cutting off their blood supply; can reduce bleeding and bulk symptoms.
• MRI-guided focused ultrasound: Uses focused ultrasound waves to heat and destroy fibroid tissue; suitable for select patients.
• Endometrial ablation: Destroys the uterine lining to reduce bleeding; not appropriate if future pregnancy is desired and may not help if fibroids distort the cavity.
• Hysterectomy: Surgical removal of the uterus; a definitive cure for fibroids and bleeding for those who do not wish to preserve fertility.

Every option has benefits and risks. Discuss effectiveness, recovery time, potential impact on fertility, and likelihood of recurrence with your clinician.

Fibroids, fertility, and pregnancy

Many people with fibroids conceive and carry healthy pregnancies. However, some fibroids—especially submucosal—can interfere with implantation or increase risks such as miscarriage, preterm birth, or malpresentation. If pregnancy is a goal, ask how fibroid location and treatment choice may affect fertility and pregnancy timing.

Living well with fibroids: practical tips

• Track your cycles: Use an app or calendar to record start dates, flow intensity, clots, and pain. This helps guide diagnosis and treatment response.
• Screen for and treat anemia: Report fatigue, dizziness, or shortness of breath; ask about iron studies and appropriate supplementation.
• Plan ahead for heavy days: Consider menstrual cups or higher-absorbency products; keep supplies on hand.
• Maintain a healthy weight and exercise: While lifestyle changes don’t shrink existing fibroids, overall health and weight management may support hormonal balance and symptom control.
• Avoid tobacco: Smoking can worsen cardiovascular health and healing.

Bottom line

Fibroids are a very common cause of irregular and heavy periods, but you don’t have to live with disruptive bleeding. From medications to minimally invasive procedures and definitive surgery, there are multiple evidence-based choices. Partner with a gynecologist to confirm the cause of bleeding, address anemia, and choose a treatment that matches your symptoms, health, and goals.

Trusted sources and further reading

• National Institutes of Health, NICHD: Uterine Fibroids
• Office on Women’s Health (U.S. HHS): Uterine Fibroids
• American College of Obstetricians and Gynecologists (ACOG): Uterine Fibroids FAQ
• U.S. Food and Drug Administration (FDA): Press releases on approved therapies for heavy menstrual bleeding associated with fibroids, e.g., Myfembree approval

This article is for educational purposes and does not replace personalized medical advice. Always consult a qualified clinician for diagnosis and treatment tailored to you.

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