PMS1, or Premenstrual Syndrome Type 1, refers to a specific category of premenstrual syndrome characterized by emotional and physical symptoms that occur in the luteal phase of the menstrual cycle. Common symptoms include mood swings, irritability, and physical discomfort such as bloating and breast tenderness. These symptoms typically resolve with the onset of menstruation. The exact cause of PMS1 is not fully understood, but it is believed to be linked to hormonal fluctuations, particularly involving estrogen and progesterone. Lifestyle factors, such as diet and stress, may also play a role in the severity of symptoms. Treatment options often include lifestyle changes, dietary adjustments, and, in some cases, medication.