Premenstrual Syndrome Premenstrual Syndrome (PMS) is a collection of physical and emotional symptoms experienced by individuals before their menstrual period, with a return to a symptom-free state after the period ends. Common symptoms of PMS include tender breasts, bloating or abdominal pain, mood swings, irritability or depression, fatigue, insomnia, headaches, and more severe cases can involve swelling in the hands, feet, and face. The primary cause of PMS is believed to be an imbalance of estrogen and progesterone levels before and after ovulation. PMS affects up to 80% of individuals in their reproductive years, with most having mild symptoms that... Learn more