Dysmenorrhoea is one of the commonest gynaecological conditions that affects the quality of life of many women in their reproductive years.   It means 'painful menstruation' and is derived from the Greek words dys, meaning painful; meno, meaning monthly; and rhoe, meaning flow. It is experienced as uterine cramps and can occur a few days prior to menstruation and/or during menstruation, and usually subsides at the end of menstruation.
Dysmenorrhoea is further defined within 2 subcategories although it is not always easy to distinguish between both subcategories based on history and examination alone:
Primary dysmenorrhoea occurs in the absence of pelvic pathology
Secondary dysmenorrhoea occurs in the presence of pelvic pathology.
The prevalence is difficult to determine because different definitions and criteria are used and dysmenorrhoea is often underestimated and undertreated.  A systematic review of chronic pelvic pain and dysmenorrhoea quotes a prevalence of between 47% to 97%.  A cross-sectional study reported dysmenorrhoea in 72% of young women at the age of 19 years, and in 15% of them, it was severe and affected daily activities.  Absenteeism from work or school on a regular basis due to dysmenorrhoea can occur in up to 17% of women.  The same study showed that up to 50% of these women were absent from work or school at least on one occasion due to dysmenorrhoea, and 7.9% of them were absent during every menstruation for at least half a day.
Factors that correlate positively with dysmenorrhoea are smoking, early menarche, nulliparity, and family history.   Dysmenorrhoea is not associated with the duration of the menstrual cycle, but it usually coexists with menorrhagia.
Primary dysmenorrhoea routinely occurs 6 to 12 months following menarche, once ovulatory cycles have been established. Pain is usually lower abdominal and cramping in nature. Pain may radiate to the back and to the inner thigh. It usually lasts from 8 to 72 hours and accompanies menstrual flow or precedes it by only a few hours. The pain can be associated with other systemic symptoms such as vomiting, nausea, diarrhoea, fatigue, and headache.
Clinical investigations fail to reveal an underlying pelvic pathology.
By contrast, secondary dysmenorrhoea often occurs years after the onset of menarche and may arise as a new symptom when the woman is in her 30s or 40s in the setting of an identifiable pelvic disease. The pain is not consistently related to menstruation alone, and may occur throughout the luteal phase of the menstrual cycle. It may also worsen as menses progresses rather than being confined to the first 24 to 48 hours of menstruation. Accompanying symptoms such as an irregular bleeding pattern, heavy periods, vaginal discharge, and dyspareunia can be suggestive of an underlying pelvic pathology. 
Common causes of secondary dysmenorrhoea are endometriosis, chronic pelvic inflammatory disease, adenomyosis, intrauterine polyps, submucous fibroids, and intrauterine devices. Less common causes include congenital uterine abnormalities, cervical stenosis, and an ovarian pathology.