Abnormal Uterine Bleeding: Causes, Evaluation, and Why Prompt Care Matters

Some month-to-month cycle variation is normal, but bleeding twice in one month (or other significant pattern changes like heavy flow, prolonged bleeding, or postmenopausal bleeding) warrants medical evaluation. Abnormal uterine bleeding (AUB) is a symptom, not a diagnosis—the underlying cause must be identified.

Potential Causes of Abnormal Uterine Bleeding

• Hormonal imbalances: Anovulation (PCOS, perimenopause, thyroid disease, hyperprolactinemia) → unopposed estrogen → irregular endometrial shedding.
• Pregnancy complications: Miscarriage, ectopic pregnancy, gestational trophoblastic disease — always rule out first in reproductive-age women.
• Structural lesions (PALM): Polyps (endometrial), Adenomyosis, Leiomyomas (fibroids — submucosal most likely to bleed), Malignancy/hyperplasia.
• Endometriosis: Ectopic endometrial tissue → inflammation, irregular bleeding, pain.
• Pelvic Inflammatory Disease (PID): Endometritis from ascending infection.
• Malignancy: Endometrial cancer (most common gynecologic cancer), cervical cancer, uterine sarcoma (rare). Risk ↑ with age, obesity, unopposed estrogen, Lynch syndrome.
• Iatrogenic: IUD (copper → heavier periods; hormonal → irregular spotting initially), hormonal contraception (breakthrough bleeding), anticoagulants, tamoxifen.
• Systemic: Liver disease, kidney disease, bleeding disorders.

Structured Evaluation (FIGO PALM-COEIN Classification)

Clinicians use this framework to categorize AUB:

• P - Polyp
• A - Adenomyosis
• L - Leiomyoma
• M - Malignancy/hyperplasia
• C - Coagulopathy
• O - Ovulatory dysfunction
• E - Endometrial
• I - Iatrogenic
• N - Not yet classified

Typical Diagnostic Pathway

1. History: Bleeding pattern, duration, volume, associated symptoms, medications, contraception, pregnancy history.
2. Pregnancy test: Mandatory first step (urine or serum hCG).
3. Pelvic exam: Cervical inspection, uterine size/mobility, adnexal masses.
4. Basic labs: CBC (anemia), TSH, prolactin, FSH/LH/estradiol (if indicated), coagulation studies if heavy bleeding/personal/family history.
5. Pelvic ultrasound (transvaginal preferred): Endometrial thickness, structural lesions, ovarian morphology.
6. Endometrial biopsy: Indicated for women >45, or <45 with risk factors (obesity, PCOS, unopposed estrogen, tamoxifen, failed medical management). Office procedure; rules out hyperplasia/cancer.
7. Hysteroscopy: Direct visualization; diagnostic and therapeutic (polyp/fibroid removal).

Why Early Diagnosis Matters

• Endometrial cancer is highly curable when caught early (stage I: 5-year survival >95%).
• Anemia from chronic bleeding impairs quality of life, cognition, exercise tolerance.
• Targeted treatment (hormonal, procedural, surgical) resolves symptoms and prevents complications.

Don't normalize abnormal bleeding. A systematic evaluation provides answers and a path forward—whether that's reassurance, medical management, or a procedure that restores quality of life.