Menstrual Disorders Overview: AUB, Dysmenorrhoea, and Amenorrhoea

Introduction

Menstrual disorders affect a substantial proportion of women at some point in their lives, yet many suffer in silence — either not seeking help or being told their symptoms are "normal." This article provides a structured overview of the three major categories of menstrual disorder: Abnormal Uterine Bleeding (AUB

Abnormal Uterine Bleeding (AUB)

AUB is an umbrella term for any bleeding that deviates from normal in frequency, regularity, duration, or volume. It affects approximately 30% of women at some point in their reproductive years and accounts for a significant proportion of gynaecological consultations.

PALM-COEIN Classification

The FIGO PALM-COEIN classification system (2011) organises AUB causes into:

Structural causes (PALM): Polyps (endometrial or cervical

Non-structural causes (COEIN): Coagulopathy (bleeding disorders including von Willebrand disease

Heavy Menstrual Bleeding (HMB)

Defined as menstrual blood loss >80 mL/cycle or lasting >8 days. It affects ~1 in 3 women at some point. The most common causes are fibroids, adenomyosis, endometrial polyps, and coagulopathies. Iron deficiency anaemia — causing fatigue, pallor, and reduced exercise tolerance — is a major complication. Management depends on the cause and the woman\'s fertility wishes: options range from the levonorgestrel IUS (Mirena

Dysmenorrhoea (Painful Periods)

Dysmenorrhoea — painful cramping during menstruation — affects up to 90% of reproductive-age women and is the leading cause of school and work absenteeism among young women.

Primary Dysmenorrhoea

Primary dysmenorrhoea is pain without underlying pathology. It results from endometrial prostaglandin (PGE2, PGF2α) release during menstruation, causing uterine contractions, ischaemia, and pain. It typically begins 1–2 years after menarche (once cycles become ovulatory) and usually improves with age and after childbirth. Lower abdominal cramping, typically starting 1–2 days before and lasting the first 1–3 days of flow, is characteristic. First-line treatments: NSAIDs (ibuprofen, naproxen) started 1–2 days before expected period onset, combined oral contraceptives, exercise, and heat application.

Secondary Dysmenorrhoea

Secondary dysmenorrhoea is pain caused by an underlying condition. It often begins after years of pain-free periods, worsens over time, and may be associated with non-menstrual pelvic pain, dyspareunia (painful sex

• Endometriosis: The most common cause. Endometrial-like tissue outside the uterus responds to hormonal cycles
• causing inflammation
• adhesions
• and pain. Affects ~10% of women; average diagnostic delay is 7–10 years.
• Adenomyosis: Endometrial glands invade the uterine muscle wall
• causing heavy
• painful periods. More common in women in their 30s–40s.
• Fibroids: Particularly submucosal fibroids (within the uterine cavity) can cause painful and heavy periods.
• Pelvic inflammatory disease (PID): Infection causing pelvic adhesions and chronic pain.

Amenorrhoea (Absent Periods)

Primary Amenorrhoea

Defined as absence of menstruation by age 15 (with otherwise normal pubertal development) or by age 13 (with no breast development). Causes include anatomical abnormalities (imperforate hymen, absent uterus — Müllerian agenesis

Secondary Amenorrhoea

Defined as absence of periods for ≥3 months in a woman with previously regular cycles, or ≥6 months with previously irregular cycles. Causes (after excluding pregnancy, the first step):

References: FIGO PALM-COEIN Classification 2011; ACOG Practice Bulletins on AUB, Endometriosis, and Amenorrhoea; NICE Heavy Menstrual Bleeding Guideline 2023.