Dysmenorrhea, also known as dysmenorrhoea, painful periods, or menstrual cramps, is pain during menstruation. It usually begins around the time that menstruation begins. Symptoms typically last less than three days. The pain is usually in the pelvis or lower abdomen.Other symptoms may include back pain, diarrhea, or nausea. In young women painful periods often occur without an underlying problem.t usually begins around the time that menstruation begins. Symptoms typically last less than three days. The pain is usually in the pelvis or lower abdomen. Other symptoms may include back pain, diarrhea, or nausea. In young women painful periods often occur without an underlying problem.