Absent Periods

Differential Diagnosis

Common Diagnoses

Occasional Diagnoses

  • Anorexia Nervosa
  • Excessive Exercise/Training
  • Severe Systemic Illness of any Kind
  • Contraception (Progestogen-only Pill, Long-Acting Reversible Contraception – Common Cause but Rarely Presented as a Symptom)
  • Hyperthyroidism
  • Hypothyroidism

Rare Diagnoses

  • Adrenal Disorders: Addison’s Disease, Cushing’s Disease, Congenital Adrenal Hyperplasia
  • Sheehan’s Syndrome
  • Arrhenoblastoma, Bilateral Ovarian Tumours
  • Prolactinoma, other Pituitary Tumours
  • Rare Structural or Chromosomal Abnormalities (Primary Amenorrhoea)
  • Anterior Pituitary Failure (Simmonds’s Disease)

Ready Reckoner

Key distinguishing features of the most common diagnoses

PregnancyWeight LossMenopauseDrugsPCOS
Breast TendernessYesNoNoNoNo
Hot FlushesNoNoYesNoNo
ObesityNoNoNoNoPossible
GalactorrhoeaYesNoNoPossibleNo
DepressionNoPossiblePossibleNoNo

Possible Investigations

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.

Top Tips

  • 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.

Red Flags

  • 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.

Published: 2nd August 2022 Updated: 3rd April 2024

Report errors, or incorrect content by clicking here.

What is Pulse Reference?

Based on the best-selling book Symptom Sorter. Pulse Reference is designed to help GPs make sense of patient presentations. It analyses a multitude of symptoms commonly seen in primary care and for each presents differentials, distinguishing features, possible investigations and key points. It also provides guides on managing more than 350 conditions. The perspective is very much grass roots primary care, informed by the latest evidence and guidance.

Learn More

Disclaimer

Pulse Reference is based on the best-selling book Symptom Sorter. The experts behind Pulse Reference are Dr Keith Hopcroft who is the co-author of Symptom Sorter, a GP in Essex and Pulse’s editorial advisor and Dr Poppy Freeman, a GP in Camden and also a clinical advisor to Pulse. This website is for clinical guidance only and cannot give definitive diagnostic information. Practitioners should work within the limits of their individual professional practice, seek guidance when necessary and refer appropriately.