Menorrhagia refers to excessive, abnormal uterine bleeding, which occurs over several consecutive cycles and interferes with a woman's physical, emotional, social, and material quality of life.

Menorrhagia is hard to define clinically. We must first consider parameters of normal menstrual bleeding. The key parameters in normal menstrual bleeding include frequency, regularity, volume and duration of menses.

  • Frequency: every 21-35 days
  • Regularity: consistent cycle frequency
  • Volume: approximately 5-80 mL of blood
  • Duration: bleeding for 5 days

Markers of menorrhagia include increased frequency of blood soaked pads/tampons or blood loss that interferes with daily activities. In the literature, menorrhagia is traditionally quoted as blood loss exceeding 80 mL. Menorrhagia is often used synonymously with heavy menstrual bleeding (HMB), which is considered to be a more precise term.


Menorrhagia is an extremely common presentation in primary care.

Approximately 1 in 20 women between the ages of 30-49 consult their GP each year. It is estimated that up to 1/3rd of women will define their periods as heavy; therefore, it is essential to consider the impact symptoms are having on their quality of life. 

Aetiology & pathology

The causes of menorrhagia can be categorised into disorders of the ovaries and uterus, systemic disorders and iatrogenic causes.

In 40-60% of cases no cause is identified. This is termed dysfunctional uterine bleeding (DUB).

Ovarian and uterine pathology

  • Uterine fibroids (leiomyomas)
  • Endometriosis & adenomyosis
  • Pelvic inflammatory disease
  • Endometrial polyps & hyperplasia
  • Polycystic ovarian syndrome

Systemic disorders

  • Coagulation disorders
  • Hypothyroidism
  • Liver/renal disease

Iatrogenic causes

  • Anticoagulants
  • Contraceptives  (e.g. IUD)


A useful mnemonic for remembering the important causes of menorrhagia is 'PERIODS'

  • P: Polyps & Pelvic inflammatory disease
  • E: Endometriosis & Endometrial carcinoma
  • R: Really bad hypothyroidism
  • I: Intrauterine contraceptive device
  • O: polycystic Ovary syndrome
  • D: Dysfunctional uterine bleeding
  • S: Submucosal fibroids

Uterine fibroids

Uterine fibroids (leiomyomas) are benign tumours that arise from the muscle layer of the uterus termed the myometrium.

They are maintained by high levels of oestrogen and progestogens. Their incidence progressively increases towards menopause and they are more common in black females. Fibroids can be classified based on location (i.e. subserosal, intramural, submucosal).

Fibroids are commonly asymptomatic, but clinical features can include menorrhagia, abdominal swelling, pelvic pain, dyspareunia, dysmenorrhoea and urinary/bowel symptoms. The diagnosis of fibroids is based on pelvic ultrasonography and treatment usually revolves around management of menorrhagia.


Intrauterine contraceptive devices (IUDs) may be used as long-term contraception and can be used as an emergency contraceptive device within 5 days of unprotected sexual intercourse.

A traditional IUD is made of copper and may be inserted for up to 10 years in duration. They are effective contraceptives that work by causing cervical mucus to be thicker in consistency and alters motility within the uterotubal system. Collectively this prevents sperm migration.

Nevertheless, IUDs have an increased risk of bleeding irregularities including menorrhagia. Compare this to newer intrauterine contraceptive systems (e.g. mirena), which may be used as a treatment for menorrhagia.

Clinical features

The cardinal symptom of menorrhagia is heavy blood loss during menstruation. 

The presence of other clinical features usually points towards an underlying pathology and can include the following:

  • Post-coital bleeding
  • Dyspareunia
  • Dysmenorrhoea
  • Intermenstrual bleeding
  • Pelvic pain and/or pressure symptoms
  • Vaginal discharge
  • Hirsutism
  • Bruises (coagulation disorders)


Diagnosis of menorrhagia relies on an agreement between patient and clinician that menstrual bleeding experienced is heavy.

Further investigations may be warranted depending on the presenting symptoms and examination findings of the patient (e.g. a pelvic mass warrants urgent investigation with imaging). Up to 40-60% of cases of menorrhagia have no underlying cause known as dysfunctional uterine bleeding.


Investigations are important to help delineate the underlying cause and assess for complications (e.g. iron-deficiency anaemia). 

Basic investigations can be arranged in primary care including pregnancy test, full blood count and pelvic ultrasound scan. Other tests are dependent on the suspected underlying cause and screening results.

Pregnancy test

A pregnancy test should be completed in all pre-menopausal patients with abnormal uterine bleeding. The test is simple and non-invasive.

Full blood count

Women with excessive bleeding are at risk of iron-deficiency anaemia due to the excess loss of blood and subsequent iron stores. Further assessment with haematinics and iron studies may be requested to confirm the diagnosis.

Pelvic ultrasound

Pelvic ultrasound is the modality of choice to assess for structural causes of menorrhagia (e.g. fibroids).

The main indications for pelvic ultrasound include palpable uterus abdominally, a pelvic mass (consider two week wait referral), and menorrhagia not responsive to conventional treatment


Other investigations are dependent on the suspected underlying cause and whether a more thorough evaluation of the underlying cause is required. 

Importantly, if there is any suspicion of gynaecological malignancy then patients should be referred urgently for specialist assessment.


The management of menorrhagia is divided into primary care or secondary care interventions.

Primary care

Management of menorrhagia in primary care is divided into first, second and third choice therapies based on the hierarchy of pharmacological therapy.

  • First choice: intrauterine contraceptive system (IUS - Mirena coil) for those not wanting to get pregnancy. Hormone-mediated contraception. Releases progestogen levonorgestrel. Increases cervical mucus preventing sperm migration and thins the endometrium lining making implantation undesirable.
  • Second choice: tranexamic acid (TXA), nonsteroidal anti-inflammatory drugs (NSAIDs), or the combined oral contraceptive pill (COCP). TXA is an anti-fibrinolytic agent that works by inhibition of plasminogen activation.
  • Third choice: oral norethisterone or long-acting progestogens. Used when others are deemed unsuitable. 

NOTE: Oral Norethisterone should be taken during the follicular stage of menstruation (e.g. days 5-26). It decreases menstrual blood flow and in some cases effects ovulation making it unsuitable in patients who wish to concieve. Long-acting progestogens such as depot medroxyprogesterone acetate can be used every 12 weeks as an IM injection to prevent menorrhagia. 

Secondary care

The management of menorrhagia in secondary care involves pharmacological or surgical approaches.

  • Pharmacological: gonadotrophin-releasing hormone (GnRH) analogues (induce hypogonadal state). Use of GnRH analogues is reserved for specialists and may be a bridge to other therapies.
  • Surgical: endometrial ablation, hysterectomy. Uterine artery embolization and myomectomy can be used for fibroids.

Referral to secondary care

Common indications for referral to secondary care include failure of medical therapy, consideration of surgery or iron-deficiency anaemia not responding to medical therapy.

Importantly, there are several 'alarm' symptoms that should make you suspicious of malignancy:

  • Persistent intermenstrual or post-coital bleeding
  • Unexplained vulval lump or vulval ulceration and bleeding
  • Palpable abdominal mass that is not obviously a fibroid
  • Clinical features of cervical cancer

Last updated: April 2021
Author The Pulsenotes Team A dedicated team of UK doctors who want to make learning medicine beautifully simple.

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