6.1. DEFINITION, CLASSIFICATION AND TERMINOLOGY
The menstrual cycle is regulated by the feedback principle ensured by a harmonious, synchronous function at all levels of the reproductive system (see Chapter 3). Menstrual disorders of varying nature and severity may arise due to:
• disruption of one or several central components of the reproductive system;
• disruption of one or several peripheral components of the reproductive system;
• compromised neuroendocrine regulation of the reproductive function with concomitant chronic morbidities.
Definition
A menstrual cycle (p. 100) is considered normal if periods (p. 110) are regular, of the same duration, at intervals ranging from 21-24 days to 35-38 days. The notion of "normal" when applied to a period implies a bleeding lasting no less than two, and no longer than seven days with a blood loss of about 80 ml, not accompanied by pain that could disrupt the normal daily routine or working ability, not requiring pain killers. A normal menstrual bleeding does not require a change of sanitary napkins oftener than once every one or two hours; presence of minor blood clots over the first couple of days is admissible.
Classification
Depending on the nature of menstrual dysfunction, the following conditions are distinguished:
• absence of periods (amenorrhea);
• hypomenorrhea (light, short, or scanty periods); hypermenorrhea (frequent, long, heavy bleeding);
• painful periods (dysmenorrhea).
Three main groups of menstrual dysfunction are distinguished in clinical practice: amenorrhea, abnormal uterine bleeding (AUB), and dysmenorrhea.
Terminology
Amenorrhea is absence of periods or cessation of spontaneous periods for 3-6 or more months.