Premenstrual syndrome (PMS) is any of a complex of symptoms experienced by some women in the days immediately before menstruation

Aetiology

• The vast majority of women (95%) get premenstrual symptoms, however to be classed as PMS the symptoms must impact on daily living
• Four in ten women (40%) experience symptoms of PMS and of these 5–8% suffer from severe PMS

Pathophysiology

• Not clearly understood
• Sensitivity to progesterone - serum concentrations of oestrogen and progesterone the same in those with and without PMS
• Serotonin receptors are responsive to oestrogen and progesterone, and selective serotonin reuptake inhibitors (SSRIs) are proven to reduce PMS symptoms
• GABA (γ-aminobutyric acid) levels are modulated by the metabolite of progesterone, allopregnanolone, and in women with PMS the allopregnanolone levels appear to be reduced

Clinical features

• Symptoms must be present in luteal phase, abate during menstruation followed by a symptom free week

Physical symptoms

• Breast tenderness
• Bloating
• Headache
• Skin disorder
• Weight gain
• Swelling
• Joint pain
• Fatigue