What is Abnormal Uterine Bleeding?

Abnormal Uterine Bleeding (AUB) refers to any variation from normal menstrual patterns, including changes in regularity, frequency, duration, or volume of menstrual flow. It is one of the most common reasons women seek gynecologic care.

Normal menstrual cycles typically occur every 24-38 days, with bleeding lasting 4.5-8 days. Menstrual blood loss greater than 80 mL per cycle is considered heavy, though in practice, the significance of bleeding is best judged by its impact on quality of life.

The PALM-COEIN Classification

The causes of AUB are organized by the internationally recognized PALM-COEIN system:

Structural Causes (PALM)

P – Polyps: Growths of the uterine lining that may cause irregular or heavy bleeding
A – Adenomyosis: Growth of endometrial tissue into the muscular wall of the uterus
L – Leiomyomas (Fibroids): Non-cancerous uterine muscle growths
M – Malignancy and hyperplasia: Precancerous or cancerous changes in the uterine lining

Non-Structural Causes (COEIN)

C – Coagulopathy: Bleeding disorders such as von Willebrand disease
O – Ovulatory dysfunction: Irregular ovulation from hormonal imbalance, PCOS, or thyroid disorders
E – Endometrial factors: Disorders of the uterine lining itself
I – Iatrogenic: Medication-related causes including hormonal contraceptives and anticoagulants
N – Not yet classified: Other causes not fitting the above categories

Evaluation

A thorough evaluation is important to identify the underlying cause:

Clinical history: Pattern, duration, and volume of bleeding; associated symptoms; medication use
Physical examination: Including pelvic exam
Laboratory tests: Blood count, iron studies, coagulation screen, thyroid function, hormonal assessment
Pelvic ultrasound: To assess the uterus for structural abnormalities
Endometrial biopsy: To evaluate the uterine lining, particularly in women over 45 or with risk factors
Hysteroscopy: Direct visualization of the uterine cavity when indicated

Treatment Options

Treatment depends on the underlying cause, severity, age, and reproductive plans:

Medical Management

Hormonal therapies: Combined oral contraceptives, progestins, or hormonal IUD (such as Mirena)
Non-hormonal therapies: Tranexamic acid, NSAIDs
Treatment of underlying conditions: Thyroid disorders, coagulation abnormalities

Procedural and Surgical Options

Endometrial ablation: Destruction of the uterine lining to reduce or stop bleeding, suitable for women who have completed childbearing
Hysteroscopic polypectomy or myomectomy: Removal of polyps or submucosal fibroids through the cervix
Laparoscopic myomectomy: Removal of fibroids while preserving the uterus
Hysterectomy: Definitive treatment when other options have been exhausted and childbearing is complete

When to Seek Care

Seek evaluation if you experience menstrual bleeding that soaks through a pad or tampon every hour for several hours, bleeding that lasts more than 7 days, bleeding between periods or after menopause, or if heavy bleeding is affecting your daily quality of life.