N91.2: Amenorrhoea, unspecified

You have missed one or more periods.

The uterus consists mainly of a layer of muscle and a lining of mucous membrane (mucosal lining). The mucosal lining receives a good supply of blood and steadily increases in size. Unless an egg is fertilized, a large part of the mucosal lining is shed and replaced. The menstrual bleeding starts when the mucosal lining is shed. The uterus is connected to the vagina. During your menstrual bleeding the mucosal lining is discharged through the vagina to the outside of the body along with some blood.

You have missed one or more periods. This can have many different causes. Menstrual bleeding may not occur if there is a change in the levels of messenger substances in the body. Menstrual bleedings are controlled by various messenger substances. Another reason menstrual bleeding may not occur is if you are under psychological stress or underweight.

Additional indicator

On medical documents, the ICD code is often appended by letters that indicate the diagnostic certainty or the affected side of the body.

  • G: Confirmed diagnosis
  • V: Tentative diagnosis
  • Z: Condition after
  • A: Excluded diagnosis
  • L: Left
  • R: Right
  • B: Both sides

Further information


This information is not intended for self-diagnosis and does not replace professional medical advice from a doctor. If you find an ICD code on a personal medical document, please also note the additional indicator used for diagnostic confidence.
Your doctor will assist you with any health-related questions and explain the ICD diagnosis code to you in a direct consultation if necessary.


Provided by the non-profit organization “Was hab’ ich?” gemeinnützige GmbH on behalf of the Federal Ministry of Health (BMG).