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Health condition

Abnormal vaginal bleeding, PALM-COEIN causes, red flags and modern UK treatment.

Heavy, between periods, after sex or after the menopause - each pattern has its own workup and its own ladder of treatment. Postmenopausal bleeding is always urgent.

Jump to treatment
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Why trust this guide

  • 01

    Editorial team

    Written by our editorial team from the UK sources listed on each page.

  • 02

    Sourced from guidance

    Checked against NICE, RCOG, BSGE and peer-reviewed sources you can see at the end.

  • 03

    Current for 2026

    Reflects modern UK guidance including PALM-COEIN classification, LNG-IUS first-line care and the two-week wait for postmenopausal bleeding.

Key facts

Abnormal vaginal bleeding at a glance.

The essentials, in plain English - what counts as abnormal, how it is classified and the tools that make the diagnosis.

  • What it is

    Any bleeding from the vagina that falls outside a normal, regular period - heavy, between periods, after sex, or after the menopause.

  • How it is classified

    PALM-COEIN groups the causes into structural (Polyp, Adenomyosis, Leiomyoma, Malignancy) and non-structural (Coagulopathy, Ovulatory, Endometrial, Iatrogenic, Not-classified).

  • Menorrhagia

    Heavy menstrual bleeding that affects quality of life - not defined by millilitres, but by how it makes you feel.

  • Postmenopausal

    Any bleeding after 12 months without a period is a red flag - a two-week-wait referral rules out endometrial cancer.

  • First-line workup

    Speculum exam, pelvic ultrasound, endometrial thickness measurement and, when indicated, hysteroscopy with biopsy.

  • Modern treatment

    LNG-IUS Mirena, tranexamic acid, hormonal options, hysteroscopic polypectomy, endometrial ablation, UAE and hysterectomy - matched to cause.

Why this guide matters

Name the pattern, then treat the cause.

Heavy, intermenstrual, postcoital and postmenopausal bleeding are different problems with different workups. Getting the label right is what unlocks the right care.

  • PALM-COEIN gives a common language

    Structural (Polyp, Adenomyosis, Leiomyoma, Malignancy) and non-structural (Coagulopathy, Ovulatory, Endometrial, Iatrogenic, Not-classified) - one framework, clear next steps.

  • Ultrasound and hysteroscopy do the heavy lifting

    Transvaginal ultrasound measures the endometrium and screens for fibroids and polyps; hysteroscopy plus biopsy is the definitive test when needed.

  • Postmenopausal bleeding is a two-week wait

    Any bleeding after the menopause is treated as suspected endometrial cancer until proven otherwise - urgent gynaecology referral, no exceptions.

How the diagnosis is made

From first appointment to a clear plan.

The steps a UK GP or gynaecologist will normally follow, in order - so you know what to expect and why each test matters.

  1. 01

    Assessing

    History and bleeding pattern

    Heavy, intermenstrual, postcoital or postmenopausal - the pattern narrows the PALM-COEIN cause before any test is done.

  2. 02

    Assessing

    Speculum and pelvic exam

    Looks for polyps, cervical lesions, atrophy, infection and pelvic masses. A cervical smear is taken if overdue.

  3. 03

    Assessing

    Bloods and STI screen

    Full blood count for anaemia, ferritin, thyroid function, coagulation screen if suggestive, plus chlamydia and gonorrhoea swabs.

  4. 04

    Confirming

    Transvaginal ultrasound

    The first imaging step - measures endometrial thickness, spots fibroids, adenomyosis and polyps. Postmenopausal thickness over 4 mm needs a biopsy.

  5. 05

    Confirming

    Hysteroscopy and biopsy

    Direct look inside the uterine cavity with a targeted endometrial biopsy - the definitive test for polyps, hyperplasia and cancer.

  6. 06

    Planning

    Two-week-wait if red flag

    Postmenopausal bleeding, or persistent unexplained bleeding over 55, triggers an urgent suspected cancer referral under NICE NG12.

  7. 07

    Planning

    Shared treatment plan

    Once the cause is clear, treatment is chosen against fertility wishes, symptom burden and cardiovascular or clotting risk.

Typical timeline: GP visit to a settled plan in weeks - postmenopausal bleeding is always fast-tracked.

Symptoms

The patterns that matter.

Heavy, between periods, after sex or after the menopause - plus the systemic clues (anaemia, pain, irregularity) that guide the workup.

  • Heavy menstrual bleeding

    Flooding, large clots, changing protection every hour - and the impact on work, sleep and mood matters more than the volume.

  • Intermenstrual bleeding

    Bleeding between periods - often from polyps, cervical ectropion, hormonal contraception or, less often, endometrial pathology.

  • Postcoital bleeding

    Bleeding after sex - cervical ectropion or polyp are common, but cervical cancer must be excluded with a smear and colposcopy.

  • Postmenopausal bleeding

    Any bleeding 12 months after the last period - a two-week-wait red flag for endometrial cancer until proven otherwise.

  • Pelvic pain and pressure

    Dysmenorrhoea, deep dyspareunia and heaviness - point to adenomyosis, fibroids or endometriosis as the underlying driver.

  • Irregular cycles

    Anovulatory cycles from PCOS, perimenopause or thyroid disease - unopposed oestrogen is a risk for endometrial hyperplasia.

  • Anaemia and fatigue

    Iron-deficiency anaemia from chronic loss - breathlessness, palpitations and pallor deserve prompt iron replacement.

  • Red flag - postmenopausal bleeding

    Bleeding after the menopause is never normal - urgent gynaecology referral and pelvic ultrasound within two weeks.

Treatment

LNG-IUS and tranexamic acid for most. Hysteroscopic surgery, ablation, UAE and myomectomy for structural causes. Hysterectomy is the definitive step when other options fail.

  • LNG-IUS (Mirena)

    NICE first-line for heavy menstrual bleeding, adenomyosis and small fibroids - reduces loss by up to 90 per cent and lasts five years.

  • Tranexamic acid

    Non-hormonal antifibrinolytic taken on heavy days - reduces flow by about a third and is often combined with mefenamic acid.

  • Mefenamic acid

    A prostaglandin inhibitor NSAID - reduces both bleeding and period pain, taken from the start of the period.

  • Combined hormonal contraception

    The combined pill, patch or ring - regulates cycles and lightens flow for suitable patients without cardiovascular risk.

  • Progestogen-only options

    Oral progestogens, the progesterone-only pill or the depot - useful when oestrogen is contraindicated.

  • Hysteroscopic polypectomy

    Day-case removal of endometrial or cervical polyps through the cervix - often diagnostic and therapeutic in one visit.

  • Endometrial ablation (NovaSure)

    Radiofrequency thinning of the endometrium in around 90 seconds - a fertility-ending option for heavy bleeding when the cavity is normal.

  • Uterine artery embolisation

    Interventional-radiology option for symptomatic fibroids - preserves the uterus and avoids major surgery.

  • Myomectomy

    Fibroid removal preserving fertility - hysteroscopic, laparoscopic or open depending on size and location.

  • Hysterectomy

    The definitive treatment when other options fail or fertility is complete - laparoscopic or vaginal where possible.

What this guide is based on

The sources behind every claim on this page.

UK national guidance and specialist society standards, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your GP or gynaecologist knows your history and can tell you which parts apply to you. If in doubt, get seen - and never wait with postmenopausal bleeding.

  • NICE. Heavy menstrual bleeding: assessment and management (NG88).

  • NICE. Suspected cancer: recognition and referral (NG12) - postmenopausal bleeding pathway.

  • RCOG. Green-top guidelines on management of endometrial hyperplasia and abnormal uterine bleeding.

  • BSGE. Standards for outpatient hysteroscopy and endometrial biopsy.

  • FIGO. PALM-COEIN classification of abnormal uterine bleeding in reproductive-age women.

Red flags

When bleeding needs urgent attention.

Most abnormal bleeding is benign and manageable. These are the situations that aren’t - and where an urgent gynaecology opinion is essential.

  • Postmenopausal bleeding

    Any bleeding 12 months after the last period is a two-week-wait suspected cancer referral - do not watch and wait.

  • Persistent bleeding over 55

    New unexplained vaginal bleeding in women over 55 warrants urgent gynaecology assessment under NICE NG12.

  • Heavy bleeding with syncope

    Flooding causing dizziness, fainting or symptomatic anaemia needs same-day assessment and possible transfusion.

  • Postcoital bleeding

    Persistent bleeding after sex needs a speculum exam, up-to-date smear and colposcopy to exclude cervical cancer.

  • Bleeding on tamoxifen or HRT

    Unscheduled bleeding on tamoxifen or sequential HRT needs prompt gynaecology review and endometrial assessment.

  • Pelvic mass or ascites

    A palpable pelvic mass, abdominal swelling or ascites with bleeding needs urgent gynae-oncology triage.

  • Pregnancy-related bleeding

    Any bleeding with a positive or possible pregnancy test needs early pregnancy assessment to exclude miscarriage or ectopic.

  • Endometrial thickness over 4 mm

    A postmenopausal endometrium over 4 mm on ultrasound needs hysteroscopy and biopsy without delay.

  • Bleeding with anticoagulants

    Heavy bleeding on warfarin, DOACs or antiplatelets needs joint gynaecology and haematology review.

Living with it

A treatable problem, with a clear ladder.

Four things that make the biggest difference day to day - track the pattern, replace lost iron, try treatments in order and escalate early if life is on hold.

A quiet reminder

Heavy bleeding is common - it is not something you have to live with.

Modern gynaecology has good, well-tolerated options at every step. Ask for the next rung on the ladder if the current one is not enough.

  1. 01 Track

    Log the pattern

    A simple period tracker or bleeding diary makes the pattern legible and speeds up the right diagnosis.

  2. 02 Iron

    Replace the losses

    Chronic heavy bleeding drains iron stores - ferritin, dietary iron and oral or IV replacement all matter.

  3. 03 Options

    Try the ladder in order

    LNG-IUS and tranexamic acid work for most - surgery is rarely the first step and rarely the only option.

  4. 04 Escalate

    Do not normalise it

    If bleeding is disrupting life, or anything has changed suddenly, ask for a gynaecology opinion sooner rather than later.

Frequently asked

Everything we get asked about abnormal bleeding.

Quick answers on PALM-COEIN, the Mirena coil, endometrial ablation and when hysterectomy is the right choice.

  • What counts as abnormal vaginal bleeding?

    Any bleeding that is heavier than usual, happens between periods, after sex, or after the menopause. It also includes cycles that are much shorter, longer or more irregular than your normal pattern. If it is affecting your daily life, it is worth investigating.

  • What is PALM-COEIN?

    A FIGO classification for abnormal uterine bleeding in women of reproductive age. PALM covers structural causes - Polyp, Adenomyosis, Leiomyoma (fibroid) and Malignancy. COEIN covers non-structural causes - Coagulopathy, Ovulatory dysfunction, Endometrial, Iatrogenic and Not-otherwise-classified. It gives clinicians a common language and helps target treatment.

  • Why is postmenopausal bleeding so serious?

    Because up to one in ten women with postmenopausal bleeding are found to have endometrial cancer. UK guidance treats it as a red flag - a two-week-wait suspected cancer referral, with a transvaginal ultrasound and, if the endometrium is thicker than 4 mm, a hysteroscopy and biopsy.

  • What is the LNG-IUS Mirena and how well does it work?

    A small hormonal coil that sits in the uterus and releases levonorgestrel locally. It is NICE first-line for heavy menstrual bleeding and often halts bleeding altogether within a year. It also helps adenomyosis, small fibroids and endometrial protection on HRT, and lasts five years.

  • What is endometrial ablation?

    A day-case procedure that thins or destroys the lining of the womb - NovaSure uses radiofrequency energy delivered in around 90 seconds. It is offered when the uterine cavity is normal, fertility is complete, and heavy bleeding has not responded to medication. It is not appropriate if a woman still wants to conceive.

  • When is hysterectomy the right choice?

    Hysterectomy is reserved for cases where medical and less-invasive surgical options have failed, or where there is a structural cause - large fibroids, adenomyosis, hyperplasia or malignancy - that will not respond otherwise. Laparoscopic and vaginal routes are preferred over open surgery where possible, and the ovaries are usually kept unless there is a specific reason to remove them.

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