Premenstrual syndrome, or PMS, refers to a group of physical and emotional symptoms that many women experience in the days leading up to their menstrual period. Common symptoms include mood swings, bloating, fatigue, and irritability. These symptoms typically occur in the luteal phase of the menstrual cycle, which is the time between ovulation and the start of menstruation. The exact cause of PMS is not fully understood, but it is believed to be linked to hormonal changes, particularly fluctuations in estrogen and progesterone. Lifestyle factors, such as stress, diet, and exercise, can also influence the severity of symptoms. Treatment options may include lifestyle changes, medication, or dietary adjustments.