What is dysmenorrhea?

Dysmenorrhea: Definition, Pathophysiology, and Management

Dysmenorrhea is defined as painful cramping in the lower abdomen occurring just before or during menstruation, with prevalence rates as high as 90% among women of reproductive age. Primary dysmenorrhea refers to menstrual pain without underlying pelvic pathology, while secondary dysmenorrhea is associated with identifiable pelvic conditions such as endometriosis or uterine fibroids. 1

Pathophysiology

Primary dysmenorrhea results from excessive production of endometrial prostaglandins, particularly PGF2α and PGE2, which cause:

• Increased uterine tone
• Stronger and more frequent uterine contractions
• Reduced uterine blood flow
• Peripheral nerve hypersensitivity 2

These changes lead to the characteristic cramping pain that typically:

• Begins shortly before or at the onset of menstruation
• Peaks within the first 24-48 hours
• May last up to 72 hours 3

Clinical Presentation

Pain Characteristics

• Cramping or colicky pain in the lower abdomen
• May radiate to the lower back and thighs
• Often described as similar to labor pains

Associated Symptoms

• Physical: headache, fatigue, back pain, breast tenderness, nausea, vomiting, diarrhea
• Psychological: irritability, anxiety, mood disturbances 3

Diagnosis

Diagnosis of primary dysmenorrhea is primarily clinical and based on:

1. Typical cramping pain that begins just before or during menstruation
2. Absence of pelvic pathology
3. Pain that typically improves with NSAIDs or hormonal contraceptives

Secondary dysmenorrhea should be suspected when:

• Pain begins after age 25
• Pain is unresponsive to NSAIDs and hormonal contraceptives
• Pain occurs outside the menstrual period
• Abnormal findings on pelvic examination 4

Management

First-Line Pharmacological Treatment

1. NSAIDs: The mainstay of treatment due to their inhibition of cyclooxygenase enzymes, which blocks prostaglandin formation

   • Ibuprofen: 400 mg every 4-6 hours as needed, beginning at the earliest onset of pain 5
   • Other effective options: naproxen sodium, ketoprofen

2. Hormonal Contraceptives: Particularly useful when contraception is also desired

   • Inhibit endometrial development
   • Decrease menstrual prostaglandin production
   • Reduce menstrual flow 2

Non-Pharmacological Approaches

Evidence-based non-pharmacological options include:

1. Heat therapy: Application of heat to the lower abdomen
2. Regular physical exercise: Helps reduce severity of symptoms
3. Other options with less robust evidence:
   • Dietary supplements
   • Acupuncture
   • Transcutaneous electrical nerve stimulation (TENS) 1

Treatment Algorithm

1. Start with NSAIDs at the earliest onset of pain
2. If inadequate relief after 2-3 menstrual cycles, add hormonal contraceptives
3. If still inadequate relief, consider:
   • Alternative NSAID
   • Non-pharmacological approaches
   • Evaluation for secondary causes of dysmenorrhea 2

Impact and Burden

Dysmenorrhea significantly impacts quality of life and productivity:

• Leading cause of recurrent short-term school or work absenteeism among young women
• Students with dysmenorrhea miss 1-2.5 days per month depending on pain severity 6
• Often undertreated and underdiagnosed despite high prevalence 4

Special Considerations

Endometriosis

Endometriosis is a common cause of secondary dysmenorrhea, characterized by:

• Presence of endometrium-like tissue outside the uterus
• Chronic inflammation and pelvic pain
• Associated with hypercholesterolemia, hypertension, and increased cardiovascular risk 7

The pain from endometriosis correlates with the depth of lesions rather than their appearance or extent 7

Treatment Resistance

Approximately 10% of women with primary dysmenorrhea do not respond to NSAIDs and hormonal contraceptives. In these cases, secondary causes should be thoroughly investigated 4

Follow-up and Monitoring

Regular follow-up is important to:

• Assess treatment efficacy
• Monitor for medication side effects
• Consider alternative or additional treatments if response is inadequate
• Evaluate for development of secondary causes if symptoms change

Primary dysmenorrhea typically improves with age and after childbirth, but persistent or worsening symptoms warrant further investigation.