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Menorrhagia (heavy menstrual bleeding)

Updated 03/03/2026
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Exam Tips

  • In UK exams, define HMB by quality-of-life impact rather than measured volume.
  • Always state FBC for all; do not routinely request ferritin, female hormone panel, or blood-loss quantification.
  • Choose investigation by suspicion: hysteroscopy first for suspected cavity pathology; ultrasound for large fibroids/pelvic mass; TVUS first-line for suspected adenomyosis.
  • Red flags for endometrial assessment/biopsy include persistent intermenstrual or irregular bleeding, obesity with infrequent heavy bleeding, tamoxifen use, and failed treatment.
  • For management viva answers, pair each drug with a dose and one key contraindication.
  • See figure in standard UK gynaecology texts for PALM-COEIN classification and typical TVUS features of adenomyosis/fibroids.

Definition

Heavy menstrual bleeding (menorrhagia) is menstrual blood loss that the patient feels is excessive and that disrupts physical, social, emotional, or material quality of life. In UK practice, diagnosis is clinical rather than volume-based, so bleeding can be significant even when measured loss is not >80 mL or duration is not >7 days.

Pathophysiology

Normal menstruation depends on coordinated hypothalamic-pituitary-ovarian cycling and controlled endometrial breakdown with local haemostasis. Heavy bleeding arises when this control fails due to structural uterine disease (for example submucosal fibroids, polyps, adenomyosis), ovulatory dysfunction (for example anovulation in PCOS causing prolonged unopposed oestrogen and unstable endometrium), endometrial haemostatic dysfunction (altered prostaglandins/fibrinolysis), iatrogenic causes (IUD or medicines), or systemic disease (for example von Willebrand disease, thyroid, liver, renal disease). FIGO PALM-COEIN is useful for mechanistic classification in exams (see figure in core gynaecology texts on AUB classification).

Risk Factors

  • Age 30-49 years (common primary-care presentation), but also frequent in adolescents
  • Fibroids, endometrial polyps, adenomyosis, endometriosis
  • PCOS/anovulatory cycles
  • Obesity (especially with infrequent heavy bleeding and endometrial risk)
  • Coagulation disorders (for example von Willebrand disease), especially bleeding since menarche
  • Thyroid disease, diabetes, hyperprolactinaemia, chronic liver or renal disease
  • Tamoxifen use
  • Drugs: anticoagulants, antiplatelets, SSRIs, NSAIDs, some hormonal contraception, herbal products (ginkgo/ginseng/soya)
  • Copper intrauterine device

Clinical Features

Symptoms

  • Perceived heavy periods (flooding, clots, frequent change of sanitary products)
  • Bleeding lasting >7 days or change from usual pattern
  • Intermenstrual or irregular bleeding (raises concern for cavity/endometrial pathology)
  • Pelvic pain/pressure, dysmenorrhoea, dyspareunia (consider adenomyosis/endometriosis/fibroids)
  • Postcoital bleeding
  • Anaemia symptoms: fatigue, exertional dyspnoea, headache, palpitations

Signs

  • Pallor or other signs of iron deficiency anaemia
  • Bulky, tender uterus (suggestive of adenomyosis)
  • Enlarged irregular uterus or palpable pelvic/abdominal mass (fibroids)
  • Cervical or vaginal lesion on speculum exam
  • Bruising/petechiae suggesting bleeding disorder
  • Goitre or hypothyroid features; acne/hirsutism suggesting PCOS

Investigations

Full blood count (all women):Low haemoglobin with or without microcytosis/hypochromia suggesting iron deficiency from chronic menstrual loss
Urine/serum pregnancy test (if pattern deviates from baseline in reproductive age):Usually negative in isolated HMB; positive result redirects diagnosis
Vaginal/cervical swabs if infection suspected:May identify infective cause of abnormal bleeding
Thyroid function tests (if hypothyroid features):Raised TSH/low free T4 in hypothyroidism-associated menstrual disturbance
Coagulation assessment (including von Willebrand testing when indicated):Abnormal coagulation profile or reduced vWF activity in inherited bleeding disorders
Outpatient hysteroscopy (first-line when cavity pathology suspected):Direct visualization of submucosal fibroids, polyps, focal endometrial abnormalities; allows targeted biopsy
Endometrial biopsy at hysteroscopy (high-risk groups):Hyperplasia or malignancy in selected high-risk patients (for example persistent irregular/intermenstrual bleeding, obesity with infrequent heavy bleeding, tamoxifen use, failed treatment)
Pelvic ultrasound (if palpable uterus/mass or difficult exam):Larger fibroids, uterine enlargement, adnexal masses
Transvaginal ultrasound for suspected adenomyosis:Bulky globular uterus, heterogeneous myometrium, myometrial cysts or fan-shaped shadowing (operator dependent; MRI if TVUS unsuitable)

Management

Lifestyle Modifications

  • Use menstrual diary/PBAC-style tracking to quantify burden and treatment response
  • Optimise iron intake and treat iron deficiency; discuss impact on work/school/mental wellbeing
  • Shared decision-making based on symptom burden, fertility wishes, contraception needs, and tolerance of side effects
  • Safety-net urgently for very heavy acute bleeding, syncope, haemodynamic compromise, or suspected malignancy

Pharmacological Treatment

Levonorgestrel-releasing intrauterine system (first-line in many women without major cavity distortion)

  • Levonorgestrel 52 mg intrauterine system (releasing about 20 micrograms/24 h), effective for up to 5 years

Reduces bleeding and provides contraception. Avoid/seek specialist advice with pregnancy, active pelvic infection, unexplained bleeding, or uterine cavity distortion (for example significant submucosal fibroids).

Antifibrinolytic

  • Tranexamic acid 1 g orally three times daily during menstruation (may increase to 1 g four times daily; max 4 g/day)

Use only during bleeding days. Contraindicated in active/history of thromboembolic disease; caution in renal impairment (dose adjustment) and macroscopic haematuria.

NSAID

  • Mefenamic acid 500 mg orally three times daily, started at onset of menses and continued while heavy bleeding persists

Helpful when dysmenorrhoea coexists. Avoid in peptic ulcer disease, severe renal disease, NSAID hypersensitivity, and aspirin-sensitive asthma; GI/renal/cardiovascular risk counselling required.

Combined hormonal contraception

  • Ethinylestradiol 30 micrograms with levonorgestrel 150 micrograms once daily in a 21/7 regimen

Can reduce bleeding and regulate cycles while providing contraception. Contraindications include migraine with aura, current/past VTE, smoking age >=35 years, uncontrolled hypertension, and some thrombophilias.

Oral progestogen (cyclical option)

  • Norethisterone 5 mg orally three times daily on days 5-26 of the cycle

Useful when estrogen-containing methods are unsuitable. Adverse effects include mood change, acne, bloating, and irregular bleeding.

Long-acting progestogen

  • Medroxyprogesterone acetate depot 150 mg IM every 12 weeks

May induce amenorrhoea over time. Counsel regarding irregular bleeding initially and bone mineral density considerations with prolonged use.

Surgical / Interventional

  • Hysteroscopic polypectomy or resection of submucosal fibroids when focal cavity pathology is present
  • Endometrial ablation for women who have completed childbearing (pregnancy is unsafe/unreliable afterward; contraception still required)
  • Myomectomy for symptomatic fibroids when uterine preservation/fertility is desired
  • Uterine artery embolisation for selected fibroid-related bleeding
  • Hysterectomy as definitive treatment after failed/unsuitable alternatives or patient preference

Complications

  • Iron deficiency anaemia
  • Reduced quality of life (physical, emotional, social, financial impact)
  • Fertility impact if underlying pathology is untreated
  • Procedure-related harms: infection, perforation, thrombosis, urinary or bowel injury, persistent discharge, haemorrhage, premature ovarian failure after UAE (higher risk >45 years)

Prognosis

Prognosis is generally good with cause-directed therapy and follow-up, and many patients achieve substantial bleeding reduction or amenorrhoea. Outcomes depend on underlying aetiology (for example fibroids/adenomyosis may recur or need procedural treatment), adherence, and correction of anaemia.

Sources & References

✅NICE Guidelines(1)

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