A group of symptoms linked to the menstrual cycle that occur in the week or two weeks before menstruation. The symptoms usually go away after menstruation begins and can include acne, breast swelling and tenderness, feeling tired, having trouble sleeping, upset stomach, bloating, constipation or diarrhea, headache or backache, appetite changes or food cravings, joint or muscle pain, trouble concentrating or remembering, tension, irritability, mood swings or crying spells, and anxiety or depression.