Primary dysmenorrhea: Primary dysmenorrhea is the most common gynecologic problem in menstruating women. It is defined as cramping pain in the lower abdomen occurring at the onset of menstruation in the absence of identifiable pelvic disease. It must be distinguished from secondary dysmenorrhea, which refers to painful menses resulting from pelvic pathology such as endometriosis. Prevalence rates are up to 90%. Several risk factors are associated with more severe episodes of dysmenorrhea: earlier age at menarche, long menstrual periods, smoking, obesity and alcohol consumption. Attempting to lose weight is also associated with increased menstrual pain. Physical activity is not associated with pain characteristics. The widely held view that menstrual pain diminishes after childbearing are inconsistent is not supported by studies.Commonest gynecologic problem in menstruating women.