What are the causes of dysmenorrhea in women of reproductive age?

Causes of Dysmenorrhea

Primary Dysmenorrhea (No Underlying Pelvic Pathology)

Primary dysmenorrhea is caused by excessive prostaglandin release from the endometrium during menstruation, leading to uterine hypercontractility, reduced blood flow, and peripheral nerve hypersensitivity. 1

Pathophysiologic Mechanism

• Prostaglandins induce frequent and dysrhythmic uterine contractions with increased basal tone and active pressure 1
• The uterus experiences reduced blood flow during these hypercontractile episodes, contributing to ischemic pain 1
• Enhanced central pain processing may amplify the pain experience, similar to other visceral pain disorders like irritable bowel syndrome 2
• This form occurs in up to 50% of menstruating women and represents dysmenorrhea without identifiable pelvic pathology 1

Key Risk Factors

• Early age of menarche increases risk 2
• Low body mass index is associated with higher prevalence 2
• Dietary habits play a contributory role 2
• Associated uterine bleeding disorders increase susceptibility 2
• Psychosocial problems including stress, depression, and anxiety are significant contributors 2, 3

Secondary Dysmenorrhea (Underlying Pelvic Pathology Present)

Secondary dysmenorrhea results from identifiable pelvic pathology, with endometriosis being the most common cause. 4

Endometriosis

• Endometriosis is the most prevalent cause of secondary dysmenorrhea, characterized by endometrium-like tissue outside the uterus 4
• Affects 2-10% of women of childbearing age 5
• Induces chronic inflammation, chronic pelvic pain, and reduced fertility 5
• Associated with hypercholesterolemia, hypertension, and increased cardiovascular disease risk 5

Uterine Fibroids (Leiomyomas)

• Occur in 10-30% of women of reproductive age, with higher risk in women of sub-Saharan African ancestry 5
• Independently associated with hypertension, cardiometabolic risk factors, and cardiovascular disease 5
• Can cause painful menstruation even in normotensive women due to extensive vascular abnormalities 5

Polycystic Ovary Syndrome (PCOS)

• Affects 8-13% of women and is one of the most common causes of menstrual disorders 5
• Characterized by hyperandrogenism, insulin resistance, and metabolic dysfunction 5
• Causes irregular, heavy, or painful menstruations through hormonal imbalance 5
• Women with PCOS have higher risk of developing hypertension and metabolic complications 5

Menstrual Disorders and Hormonal Dysfunction

• Heavy, painful, or irregular menstruations increase risk of dysmenorrhea 5
• Premenstrual syndrome (somatic and psychological symptoms 1-2 weeks before menstruation) contributes to painful periods 5
• Both early and late menarche are associated with increased dysmenorrhea risk 5

Pituitary and Hormonal Causes

• Hyperprolactinemia accounts for approximately 20% of secondary amenorrhea cases but can also cause dysmenorrhea when menstruation occurs 6
• Functional hyperprolactinemia causes polymenorrhea, oligomenorrhea, or painful menstruation 5, 6

Clinical Pearls and Common Pitfalls

Prevalence and Impact

• Dysmenorrhea affects 50-90% of women of reproductive age globally, making it the most common gynecological disorder 3
• The condition causes substantial absenteeism, lower productivity, and significant economic losses 3
• Among healthcare workers and students, dysmenorrhea impacts daily activities to a disabling degree in nearly one-third of cases 3

Diagnostic Considerations

• Primary dysmenorrhea diagnosis requires a thorough history with negative pelvic examination findings 1
• Secondary dysmenorrhea requires investigation for underlying pathology, particularly endometriosis, fibroids, or PCOS 4
• Do not dismiss severe dysmenorrhea as "normal cramps"—investigate for secondary causes if pain is severe or progressively worsening 4
• Ethnic variations in prevalence may reflect cultural attitudes toward menstruation and pain reporting 2

Treatment Implications

• Understanding the cause (primary vs. secondary) is essential because treatment approaches differ fundamentally 7, 4
• Primary dysmenorrhea responds to prostaglandin inhibition (NSAIDs) and hormonal contraception 1
• Secondary dysmenorrhea requires treatment of the underlying pathology (e.g., endometriosis management, fibroid treatment) 4