Premenstrual syndrome (PMS) is a set of physical and emotional symptoms — mood swings, irritability, low mood, bloating, breast tenderness, and fatigue — that appear in the one to two weeks before a period and ease once it starts.

During perimenopause, fluctuating estrogen and progesterone can make PMS — or its more severe form, premenstrual dysphoric disorder (PMDD) — feel worse for some women, with stronger mood swings and irritability.

Lifestyle steps (regular exercise, sleep, limiting caffeine and alcohol) help many people, and a clinician can advise on further options if symptoms disrupt your life.