Menorrhagia (heavy menstrual bleeding) is defined as excessive menses in an otherwise normal menstrual cycle. It is largely a subjective definition as what constitutes heavy bleeding to one women may be quite normal for another.

NICE suggest that for clinical purposes, heavy menstrual bleeding (HMB) should be defined as excessive menstrual blood loss which interferes with the woman's physical, emotional, social and material quality of life, and which can occur alone or in combination with other symptoms. Any interventions should aim to improve quality of life measures (1).

Older texts would define menorrhagia when menses associated with:

• clots
• the use of towels rather than tampons
• flooding
• associated dysmenorrhoea

Objectively, menorrhagia has been defined as blood loss more than 80 mls in an otherwise normal menstrual cycle (2). This value was chosen since it appears to be the maximum amount that a woman on a normal diet can lose per cycle without becoming iron deficient. In practice, actual blood loss is rarely measured.

Reference:

1. NICE (January 2007). Heavy menstrual bleeding.
2. Bonnar J, Shpppard B. BMJ 1996; 313: 579-82.
3. BNF 6.4