The menstrual cycle normally occurs monthly throughout a woman’s reproductive years as the lining of the womb (uterus) gradually grows in thickness and is shed at the period (menstruation).The average length of the menstrual cycle (from the first day of bleeding to the first of another) is 28 days but this is only an average and can vary greatly between women. Also an individual woman may find that the length of her menstrual cycle varies from month to month.
What causes PMS?
The precise causes of PMS have still to be identified but there is compelling evidence that symptoms are directly related to the fluctuation of hormone levels in the monthly cycle. As PMS is absent before puberty (onset of menstruation), in pregnancy and after the menopause there is clear indication that cyclical ovarian activity is an important factor in explaining PMS.
What are the symptoms of PMS?
PMS is characterised by a number of symptoms- over 150 have been identified
Common psychological and behavioural symptoms are: mood swings, depression, tiredness, fatigue or lethargy, anxiety, feeling out of control, irritability, aggression, anger, sleep disorder, food cravings
Common physical symptoms are: breast tenderness, bloating, weight gain, clumsiness, headaches
No-one experiences all identified symptoms. One symptom may be dominant. Each symptom may vary in severity during a cycle and from one cycle to another. New symptoms may present during a woman’s experience of PMS.
PMS symptoms may be experienced continuously from ovulation to menstruation, for 7 days before, at ovulation for3-4 days and again just prior to menstruation and in other patterns. Some women do not experience relief from symptoms until the day of the heaviest flow.