Key distinguishing features of the most common diagnoses
Likely: Pregnancy test.
Possible:FBC, U&E, TFT, FSH/LH, testosterone, SHBG, prolactin, ultrasound.
Small Print:CT with or without other imaging.
- Pregnancy test whatever contraception is used: Urinary HCG. Remember small false negative rate
- FBC, U&E, TFT: To assess for general severe systemic illness, adrenal disorders and hypo- or hyperthyroidism.
- FSH, LH, testosterone and SHBG: LH and testosterone may be high in PCOS (and SHBG normal or low), FSH very high in menopause.
- Prolactin levels high in prolactinoma and with some drugs (e.g. phenothiazines)
- Ultrasound useful to show multiple ovarian cyst formation and is a reliable check of pregnancy.
- Specialist will arrange CT or similar imaging if prolactinoma suspected.
- Amenorrhoea is common in young women, especially at times of stress; once pregnancy has been excluded and in the absence of any worrying symptoms or signs, only investigate if the problem persists beyond 6 months.
- It is important to confirm a possible diagnosis of premature menopause, as the patient will require hormone-replacement therapy (HRT).
- The same pathologies can cause both amenorrhoea and oligomenorrhoea, therefore take the same clinical approach to both.
- Advise the patient that a pregnancy test is standard practice even if they don't consider pregnancy a possibility.
- Consider anorexia – an anorectic body may be well hidden under baggy clothing, and the disease often presents with the absence of periods.
- Early morning headache and visual disturbance associated with amenorrhoea suggest possible intracranial pathology – refer urgently
- Before attributing amenorrhoea to weight loss, make sure that the weight loss itself hasn’t been caused by thyrotoxicosis.