RESUMEN
Premenstrual syndrome (PMS) is a group of psycho behavioural symptoms experienced by many susceptible young women prior to menstruation. It is suggested that there is altered autonomic activity in the late leuteal phase of their endometrial cycle. The present study is aimed to see the autonomic reactivity in women suffering from PMS and to compare it with control ones. The results revealed that the autonomic activitysympathetic as well as parasympathetic, is insignificantly higher in PMS group during follicular phase. During leuteal phase, the parasympathetic activity is significantly lowered but the sympathetic activity is significantly increased. A positive correlation was also seen between both limbs of autonomic system with number of symptoms. It appears that increased sympathetic activity coupled with decreased parasympathetic activity during the leuteal phase might be responsible for psycho- physiological changes in these women. However, the exact mechanism is still unknown.