This document discusses premenstrual changes (PMCs), also known as premenstrual syndrome (PMS) or premenstrual dysphoric disorder (PMDD). PMCs involve both psychiatric and gynecological symptoms that occur cyclically in the luteal phase before menstruation. Symptoms can range from mild mood changes to severe mental and physical disturbances. While the exact causes are unclear, serotonin levels are believed to play a role. Treatment involves lifestyle modifications and medications depending on symptom severity, with selective serotonin reuptake inhibitors and calcium supplements showing effectiveness for more severe symptoms.