Consider starting pharmacological treatment for HMB without investigating the cause if the woman's history and/or examination suggests a low risk of fibroids, uterine cavity abnormality, histological abnormality or adenomyosis (1).
If cancer is suspected then consult urgent gynaecological cancer guidance (linked below).
- laboratory investigations 
- blood tests  
- full blood count - should be undertaken on all women with heavy menstrual bleeding (HMB)
 - clotting studies - testing for coagulation disorders such as von Willebrand's disease should be considered in women who have had HMB since menarche and have personal or family history suggesting a coagulation disorder
 - serum ferritin test should not routinely be carried out on women with HMB - undertaken if the woman has been found to be anaemic on full blood count
 - female hormone testing should not be carried out on women with HMB
 - TFTs should be undertaken only when other signs and symptoms of thyroid disease are present (1)
 
 - cervical smear if indicated
 - HVS, chlamydia screen if infection suspected
 
 - structural and histological investigations
- for suspected cancer guidance then see linked item
- if appropriate, a biopsy should be taken to exclude endometrial cancer or atypical hyperplasia
- indications for a biopsy include, for example, persistent intermenstrual bleeding, and, in women aged 45 and over, treatment failure or ineffective treatment
 
 - imaging studies are indicated in various circumstances: 
- if the uterus is palpable abdominally
 - vaginal examination reveals a pelvic mass of uncertain origin
 - failure of pharmaceutical treatment
 - ultrasound is the first-line diagnostic tool for identifying structural abnormalities
 
 
 
 - hysteroscopy - used as a diagnostic tool only when ultrasound results are inconclusive, for example, to determine the exact location of a fibroid or the exact nature of the abnormality
 - dilatation and curettage alone should not be used as a diagnostic tool
 
Note:
- pregnancy test
- pregnancy should be considered as a cause for an acute onset unexplained HMB
 
 - take into account the woman's history and examination when deciding whether to offer hysteroscopy or ultrasound as the first-line investigation 
- Women with suspected submucosal fibroids, polyps or endometrial pathology 
- outpatient hysteroscopy should be offered to women with HMB if their history suggests submucosal fibroids, polyps or endometrial pathology because: 
- they have symptoms such as persistent intermenstrual bleeding or
 - they have risk factors for endometrial pathology: 
- women with persistent intermenstrual or persistent irregular bleeding, and
 - women with infrequent heavy bleeding who are obese or have polycystic ovary syndrome
 - women taking tamoxifen women for whom treatment for HMB has been unsuccessful
 
 - endometrial biopsy should be considered at the time of hysteroscopy for women who are at high risk of endometrial pathology
 
 - for women who decline hysteroscopy, consider pelvic ultrasound, explaining the limitations of this technique for detecting uterine cavity causes of HMB
 
 - Women with possible larger fibroids
- pelvic ultrasound should be offered to women with HMB if any of the following apply: 
- their uterus is palpable abdominally
 - history or examination suggests a pelvic mass
 - examination is inconclusive or difficult, for example in women who are obese
 
 
 - Women with suspected adenomyosis 
- transvaginal ultrasound (in preference to transabdominal ultrasound or MRI) should be offered to women with HMB who have:
- significant dysmenorrhoea (period pain) or
 - a bulky, tender uterus on examination that suggests adenomyosis
 
 - if a woman declines transvaginal ultrasound or it is not suitable for her, consider transabdominal ultrasound or MRI, explaining the limitations of these techniques
 - be aware that pain associated with HMB may be caused by endometriosis rather than adenomyosis
 
 
 
Reference:
- Heavy menstrual bleeding: assessment and management.  NG88. NICE Guideline (March 2018 - updated May 2021)