Abnormal Uterine Bleeding

Understanding causes, diagnosis, and treatment options

What is Abnormal Uterine Bleeding?

Full Circle Women's Care

Abnormal uterine bleeding (AUB) is bleeding from the uterus that differs from what is normal for a woman who is not pregnant. It can vary in how long it lasts, how regularly it occurs, and how heavy it is.

AUB is one of the most common reasons women visit a gynecologist — accounting for about one-third of all outpatient gynecology visits. You are not alone, and effective care is available.

Who it affects

Up to one in three women will experience AUB during their lifetime, most commonly in adolescence and perimenopause.

Acute vs. chronic

Acute AUB is a sudden, heavy episode requiring prompt care. Chronic AUB has been present for six months or more.

Why it matters

Untreated AUB can cause anemia, affect quality of life, and — in some cases — signal a condition that needs early treatment.

Good news

Most causes of AUB are benign and highly treatable. Early evaluation leads to the best outcomes.

AUB Can Involve Any of These Patterns

Heavy bleeding Prolonged periods Irregular cycles Spotting between periods Bleeding after sex Postmenopausal bleeding Very frequent periods Infrequent periods

Because pelvic bleeding can have many causes — some straightforward and some more serious — it's important to see a healthcare provider so the right diagnosis and care plan can be put in place for you.

Understanding what a typical menstrual cycle looks like makes it easier to recognize when something has changed. Bleeding that falls outside the ranges below — in frequency, duration, or volume — is considered abnormal and worth discussing with your provider.

A Normal Menstrual Cycle

24–38 Days between periods (cycle length)

2–7 Days of bleeding (period duration)

5–80 mL Total blood loss per cycle

Signs Your Bleeding May Be Abnormal

✔Periods more often than every 24 days
✔Periods less often than every 38 days
✔Bleeding lasting more than 7 days
✔Soaking a pad or tampon every hour for 2+ hours in a row

✔Spotting or bleeding between periods
✔Bleeding after sex
✔Any bleeding after menopause
✔Cycles that are noticeably heavier or lighter than your usual pattern

Tracking your cycle is one of the most helpful things you can do. Before your visit, note the dates your bleeding starts and stops, how heavy it is (light, moderate, heavy, or spotting), and any other symptoms. A smartphone app or printed calendar works great.

Adolescents and perimenopause are exceptions — but still worth discussing. Irregular cycles are common in the first few years after a first period and as menopause approaches. Even so, very heavy or prolonged bleeding at any age deserves evaluation.

There are many possible causes of abnormal uterine bleeding, and more than one may be present at the same time. Providers use a classification system called PALM-COEIN to organize causes into structural (things visible on imaging) and non-structural (hormonal or systemic) categories.

Structural Causes

These involve a physical abnormality in or around the uterus that can often be seen on ultrasound or during a procedure.

Uterine fibroids (leiomyomas) Uterine polyps Adenomyosis Endometrial hyperplasia Endometrial cancer

Non-Structural Causes

These involve hormonal, systemic, or medication-related factors rather than a visible physical abnormality.

Ovulatory dysfunction (PCOS, thyroid disease) Bleeding disorders (e.g., von Willebrand disease) Hormonal contraceptives Blood thinners or aspirin Copper IUD Perimenopause or adolescence

Other Contributing Causes

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Endometriosis Tissue similar to the uterine lining grows outside the uterus, causing heavy and often painful periods.
✔
Pelvic inflammatory disease (PID) An infection of the upper reproductive tract that can cause irregular or heavy bleeding.
✔
Pregnancy-related causes Ectopic pregnancy and miscarriage can both present as abnormal uterine bleeding.

Up to 20% of women presenting with heavy menstrual bleeding have an underlying bleeding disorder — a factor that is often overlooked. Let your provider know if heavy periods run in your family or if you've had prolonged bleeding after surgery or dental work.

Finding the cause of abnormal uterine bleeding starts with a conversation. Your provider will take a thorough history and tailor testing to your situation — starting simple and only adding more involved steps when needed.

You know your body best. The more detail you can share about when bleeding occurs, how heavy it is, and what else you've noticed, the easier it is for your provider to identify the cause and get you to the right care sooner.

What to Expect

1

Medical and menstrual history Your provider will ask about your cycle patterns, past illnesses and surgeries, current medications (including over-the-counter drugs), birth control method, and family history of bleeding disorders.
2

Pregnancy test A pregnancy test is usually the first step, since pregnancy-related causes — including ectopic pregnancy — must be ruled out early.
3

Blood tests A complete blood count (CBC) checks for anemia. Hormone levels, including thyroid-stimulating hormone (TSH) and prolactin, help identify hormonal causes. Coagulation tests may be ordered if a bleeding disorder is suspected.
4

Transvaginal ultrasound The most common first imaging test. It evaluates the uterus and ovaries for fibroids, polyps, and other structural abnormalities.
5

Sonohysterogram or hysteroscopy (if needed) Saline infusion sonography (SIS) and hysteroscopy provide a clearer view of the uterine cavity and are used when ultrasound findings are inconclusive or when a targeted lesion needs to be identified.
6

Endometrial biopsy (when indicated) A small sample of the uterine lining is examined under a microscope. Typically recommended for women over 45, or for anyone with risk factors for endometrial cancer or who has not responded to initial treatment.

Keeping a bleeding diary before your appointment makes a real difference. Note the dates your bleeding starts and stops, how heavy it is each day, and any associated symptoms such as pain or clots. ACOG offers a printable bleeding diary for this purpose.

Treatment for AUB is personalized to you. Your provider will consider the underlying cause, severity of bleeding, your age, future fertility goals, and other health factors before recommending a plan. Medical management is almost always tried first.

Medication Options

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Hormonal contraceptives Combined oral contraceptives and progestin-only pills or injections help regulate the cycle and reduce bleeding volume. The hormonal IUD (levonorgestrel-releasing) is one of the most effective medical treatments for heavy menstrual bleeding.
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Tranexamic acid A non-hormonal medication that helps blood clot and can significantly reduce menstrual blood loss. It is taken only during the days of heavy bleeding.
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NSAIDs (e.g., ibuprofen, naproxen) Reduce both bleeding and cramping by lowering prostaglandins. Most effective when started one to two days before the period begins.
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GnRH agonists Medications that temporarily stop the menstrual cycle. Often used before surgery to shrink fibroids or manage severe bleeding.
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Treatment of the underlying cause Thyroid medication for thyroid-related AUB, antibiotics for PID, or adjusted contraception if a medication is the source of the problem.

Procedural & Surgical Options

Endometrial ablation

Destroys the uterine lining to reduce or stop bleeding. Not an option for those who wish to become pregnant.

Myomectomy

Surgical removal of fibroids while leaving the uterus intact. An option for women who want to preserve fertility.

Uterine artery embolization

Blocks blood flow to fibroids, causing them to shrink. A minimally invasive alternative to surgery.

Hysterectomy

Removal of the uterus — a permanent and definitive solution for women who have completed childbearing and for whom other treatments have not worked.

Many cases of AUB are resolved with medication alone. Your care team will start with the least invasive approach and move to procedures only when needed. You will always be part of the decision-making process.

Any change in your usual bleeding pattern deserves attention. Some situations call for a routine appointment; others require prompt or emergency care. Use the guide below to help you decide.

Schedule a Routine Appointment If You Have:

✔Periods that are heavier, longer, or more irregular than usual for you
✔Spotting or bleeding between periods that recurs
✔Bleeding after sex
✔Cycles that are unpredictable or have changed significantly
✔Fatigue, weakness, or shortness of breath that may suggest anemia from blood loss
✔A family history of bleeding disorders and heavy periods since your first cycle

Postmenopausal bleeding — any bleeding 12 or more months after your last period — should always be evaluated promptly. While it is often benign, it can be an early sign of endometrial cancer, which is most treatable when found early.

Seek Emergency Care Immediately If:

⚠ You are soaking through a pad or tampon every hour for more than 2 hours in a row
⚠ ANDyou also have chest pain, shortness of breath, lightheadedness, or dizziness

These symptoms together may indicate significant blood loss. Call 911 or go to your nearest emergency room.

When in doubt, call us. Our team is here to help you determine whether your symptoms need to be seen right away, at a scheduled appointment, or can be monitored at home. You never have to figure it out alone.

Track your cycle Note symptom changes Keep a bleeding diary Don't wait if concerned Routine exams matter