Abnormal uterine bleeding !
Abnormal uterine bleeding is bleeding from the uterus that is too heavy, too long, irregular or between periods, outside pregnancy; it has many causes.
Updated 2026-10-29
Structures involved
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In embryology
In the clinical exam
In physiology
- Primary hemostasis and platelets
- Body iron balance
- The menstrual cycle: ovary and endometrium
- Menopause
Why it happens
What it is
Bleeding from the uterus that is abnormal in frequency, regularity, duration or volume, or that occurs between periods, in a woman who is not pregnant. It is a symptom with many causes, sorted with the FIGO PALM-COEIN system.
Who gets it
One of the most common reasons for gynaecological consultation, from adolescence to perimenopause. Heavy menstrual bleeding is a frequent cause of iron deficiency anaemia in women in Colombia and worldwide.
Causes
- Structural (PALM): polyp, adenomyosis, leiomyoma (fibroid), malignancy or hyperplasia
- Non-structural (COEIN): coagulopathy, ovulatory dysfunction, endometrial, iatrogenic, not yet classified
- Ovulatory dysfunction is common at the extremes of reproductive life and in polycystic ovary syndrome
Risk factors
- Adolescence and perimenopause (anovulatory cycles)
- Obesity and polycystic ovary syndrome
- Thyroid disease or hyperprolactinaemia
- Anticoagulants or bleeding disorders such as von Willebrand disease
- Hormonal contraception or intrauterine devices
Pathophysiology
In normal cycles, progesterone withdrawal triggers an orderly shedding of a stable endometrium. Without ovulation, unopposed estrogen builds a thick, fragile endometrium that sheds irregularly. Structural lesions increase surface area or disturb contraction, and clotting disorders impair haemostasis.
Classification
- PALM-COEIN (FIGO): PALM structural causes, COEIN non-structural causes
- Acute (heavy enough to need urgent intervention) or chronic (present for most of the past six months)
- Patterns: heavy menstrual bleeding, intermenstrual bleeding, irregular, frequent or infrequent bleeding
Symptoms and signs
- Heavy or prolonged periods, sometimes with clots or flooding
- Bleeding between periods or after intercourse
- Irregular or unpredictable cycles
- Fatigue, breathlessness or dizziness from anaemia
Diagnosis
- Clinical
- Detailed bleeding history, pregnancy and contraceptive status, medications and bleeding symptoms; speculum examination to look for cervical or vaginal causes.
- Tests
- Pregnancy test (hCG); complete blood count and ferritin; TSH and prolactin when indicated; coagulation studies and von Willebrand testing if a bleeding disorder is suspected; cervical screening if due. Endometrial biopsy for women 45 and older or younger women with persistent bleeding or unopposed estrogen.
- Imaging
- Transvaginal ultrasound looks for fibroids, polyps and adenomyosis; saline infusion sonohysterography or hysteroscopy for the uterine cavity; MRI in selected cases.
Differential diagnosis
- Pregnancy-related bleeding (miscarriage, ectopic pregnancy)
- Cervical lesions or cervicitis
- Vaginal trauma or atrophy
- Bleeding from the urinary tract or rectum
Goal of treatment
Stop acute bleeding, find and treat the cause, correct anaemia and reduce future bleeding in line with the woman's fertility wishes.
Treatment
- Acute
- In acute heavy bleeding: haemodynamic support, intravenous or high-dose hormonal therapy and antifibrinolytics; uterine tamponade or curettage when these fail.
- Medical
- Levonorgestrel intrauterine system, combined hormonal contraceptives or progestins for chronic heavy or anovulatory bleeding.
- Medical
- Antifibrinolytics (tranexamic acid) and non-steroidal anti-inflammatory drugs during menses; iron to correct deficiency.
- Surgical
- Polypectomy, myomectomy, endometrial ablation or hysterectomy according to the cause and fertility wishes.
Drugs for this condition
Complications
- Iron deficiency anaemia
- Hypovolaemic shock in acute heavy bleeding
- Missed endometrial hyperplasia or cancer
- Reduced quality of life and missed school or work
Prognosis
Most causes can be controlled with medical or minimally invasive treatment. Anovulatory bleeding in adolescence often settles as cycles mature.
Test yourself
Think of the answer, then tap the question to see it.
What does the acronym PALM-COEIN stand for?
Polyp, Adenomyosis, Leiomyoma, Malignancy/hyperplasia; Coagulopathy, Ovulatory dysfunction, Endometrial, Iatrogenic, Not yet classified.
Which test is done first in every woman of reproductive age with abnormal bleeding?
A pregnancy test.
Which bleeding disorder should be considered in an adolescent with heavy periods since menarche?
Von Willebrand disease.
When is endometrial sampling usually recommended in abnormal uterine bleeding?
From about age 45, or earlier with persistent bleeding, unopposed estrogen exposure, obesity or failed treatment.
Why does anovulation cause irregular heavy bleeding?
Without progesterone, unopposed estrogen builds a thick, unstable endometrium that sheds irregularly.
Related conditions
- Uterine fibroids (leiomyomas)
- Adenomyosis
- Endometrial cancer
- Polycystic ovary syndrome
- Hypothyroidism
- Iron deficiency anaemia
Educational information, not medical advice. For any symptom, see a health professional.
Sources: Abnormal Uterine Bleeding (StatPearls (NCBI Bookshelf), 2025).
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