Synopsis
Organise abnormal uterine bleeding into structural and non-structural mechanisms, use pattern and risk to select imaging or hysteroscopy, and recognise when more than one cause is contributing.
- PALM describes structural causes: polyp, adenomyosis, leiomyoma, and malignancy or hyperplasia; COEIN describes coagulopathy, ovulatory dysfunction, endometrial dysfunction, iatrogenic causes and causes not otherwise classified.
- The framework organises mechanisms rather than declaring one final diagnosis; fibroids and anticoagulation, adenomyosis and anovulation, or a polyp and hormonal contraception can coexist.
- Pregnancy-related, cervical, vaginal, vulval, urinary and rectal bleeding sit outside non-pregnant uterine classification and must be localised first.
Key red flags
Postmenopausal bleeding, persistent intermenstrual bleeding, suspicious cervix, new pelvic mass or unexplained weight loss requires prompt cancer-pathway assessment.
Investigation priorities
Remove pregnancy-related and non-uterine bleeding from the classification before uterine testing.
Management branches
Bleeding is heavy, irregular, intermenstrual, postcoital or prolonged.
- Establish pregnancy status and anatomical source, then describe cycle regularity, duration, volume impact, pain and non-menstrual bleeding.
- Review pelvic symptoms, examination, bleeding history, endocrine phenotype and treatment exposure to populate plausible PALM and COEIN categories.