Effects and analysis of the menstrual cycle.

The menstrual cycle is much more than a cycle of periods. Menstruation is only one manifestation of the ovarian cycle which is itself associated with more than 200 physical, psychological and behavioural changes. Numerous medical disorders also appear to be modulated by cyclical ovarian activity. Objective assessment of these cyclical changes can be difficult. One approach is by trend analysis, which can be used to provide both qualitative and quantitative information concerning daily menstrual cycle data. The application of this technique to the assessment of menstrual cycle symptoms and the premenstrual syndrome are demonstrated.