What are the causes of dysmenorrhea?

Causes of Dysmenorrhea

Primary Dysmenorrhea

Primary dysmenorrhea is caused by excessive production and release of prostaglandins from the endometrium, leading to increased uterine contractility, muscle ischemia, and hypoxia that manifests as menstrual pain. 1, 2, 3

Pathophysiology

• Prostaglandin overproduction by the endometrium triggers uterine hypercontractility, resulting in reduced blood flow to the uterine muscle and subsequent ischemic pain 4, 1
• This occurs in the absence of identifiable pelvic pathology on examination or imaging 4, 2
• Pain typically begins at or shortly after menarche and is most severe during the first 1-3 days of menstruation 4, 5

Clinical Presentation

• Suprapubic cramping pain that is spasmodic in nature 4
• Associated symptoms may include headaches, nausea, and vomiting 5
• Physical examination is characteristically normal 2, 5
• Affects 41-91.5% of menstruating women, making it the most common gynecological condition in reproductive-age women 1, 5

Secondary Dysmenorrhea

Secondary dysmenorrhea results from identifiable pelvic pathology and presents with similar pain patterns but has underlying structural or disease-related causes. 4, 5

Endometriosis

• Endometriosis is a major cause of secondary dysmenorrhea, characterized by deep dyspareunia exaggerated during menses and sacral backache with menstruation 6
• Pain severity correlates with the depth of endometriosis lesions rather than the extent of visible disease 6
• Painful lesions typically involve peritoneal surfaces innervated by peripheral spinal nerves 6

Uterine Fibroids (Leiomyomas)

• Fibroids are the most common uterine neoplasm and a frequent cause of dysmenorrhea, particularly in perimenopausal women 6
• Acute pain from fibroids may result from torsion of pedunculated fibroids, prolapse of submucosal fibroids, or acute infarction/hemorrhage in degenerating fibroids 6
• Prevalence exceeds 80% in Black women and approaches 70% in White women by age 50 6

Other Structural Causes

• Ovarian cysts account for approximately one-third of gynecologic pain cases in perimenopausal and postmenopausal women 6
• Cervical stenosis can cause isolated endometritis and dysmenorrhea 6
• Congenital uterine malformations and pelvic adhesions contribute to secondary dysmenorrhea 4
• Intrauterine devices (IUDs) cause dysmenorrhea through excessive prostaglandin production and release 4

Pelvic Inflammatory Disease

• Pelvic infections account for 20% of acute pelvic pain cases and include tubo-ovarian abscess, oophoritis, salpingitis, endometritis, and cervicitis 6
• Most cases relate to sexual activity, though recent instrumentation and surgery are common iatrogenic causes 6

Common Diagnostic Pitfall

The key distinction between primary and secondary dysmenorrhea is the presence or absence of identifiable pelvic pathology—laparoscopy should only be pursued if pelvic abnormality is detected on examination or if treatment with prostaglandin inhibitors fails after six months. 4

• Initial diagnosis is primarily clinical, based on history and physical examination 1, 2
• Imaging with ultrasound is useful to exclude secondary causes such as endometriosis, adenomyosis, and fibroids 3
• Pregnancy testing should be performed first to exclude pregnancy as a cause of pain 6