Amenorrhoea is the term for the lack of menstrual function in women. This means that the woman experiences no menstrual bleeds and will be infertile. Amenorrhoea may be primary amenorrhoea or secondary amenorrhoea.
Primary amenorrhoea is when the woman has never had a menstrual cycle or menstrual bleed. It occurs in about 3 in 1000 women.
Secondary amenorrhoea is when a woman has had menstrual periods in the past but these have now stopped. This occurs in about 3 in 100 women. The previous menstrual activity may have been quite brief but has shown that the woman’s hormones were once functioning in a relatively normal way.
Menstrual function depends on a number of factors that the clinician has to consider. These include:
- Genetic factors
- Weight
- Diet
- Health, including exercise and stress
- Drugs
- Activity of hormones from the brain and ovary
- Structure of the reproductive tracts
- Endocrine disease e.g. thyroid hormone disorder
- A long-term illness
- Pregnancy
Sometimes the cause of amenorrhoea may be straightforward such as pregnancy, the effect of certain drugs or due to intensive exercise. Even another chronic illness can cause amenorrhoea. In other cases the cause is not immediately obvious and may require extensive investigation.