Every month, a woman’s body prepares itself for the possibility of conception and pregnancy by going through a menstrual cycle. During the menses phase of the menstrual cycle, commonly called a period, the endometrial lining of the uterus is sloughed off and is later replaced. This process is triggered by a shift in the levels of hormones generated by the pituitary gland and the ovaries. These hormonal changes can cause the physical and emotional stresses of premenstrual syndrome, or PMS, including headaches, cramping, breast tenderness, nausea, and mood swings. Exercise, rest, stress reduction, and a healthy diet may help alleviate some symptoms of PMS. A doctor or healthcare provider can also prescribe medication to help alleviate severe PMS symptoms.