creation date: 2026-04-01 00:16
tags: Pathologies
Primary Dysmenorrhea
Background
Definitions
Dysmenorrhea refers to painful menstruation. It can be a primary process or secondary to other pelvic pathology.
Dysmenorrhea affects quality of life, school/work productivity, and performance of daily activities.
Primary dysmenorrhea is diagnosed in the absence of demonstrable disease that could account for the symptoms. This is typically made in adolescents and young females as a diagnosis of exclusion.
Pathogenesis
During menstruation, prostaglandins released induce nonrhythmic, high frequency uterine contractions. These contractions result in high intrauterine pressures (often ≥150 mmHg), which when exceeding arterial pressure, results in uterine ischemia.
Anaerobic metabolites accumulates and stimulates type-C pain neurons resulting in pain.
Clinical Presentation
Signs & Symptoms
Pain characteristics are typically:
- Recurrent, crampy; may be continuous dull ache
- Localized to lower abdomen and suprapubic area; typically midline
- Occurs 1-2 days before or with the onset of menstrual bleeding
- Gradually diminishes over 12-72 hours (but may persist until menstruation ends)
Associated symptoms include:
- Nausea
- Diarrhea
- Fatigue
- Headache
- General malaise
History & Physical Exam
History includes ascertaining the characteristics and timing of the pain, including obtaining a menstrual history.
Additionally:
- Prior treatments
- Past medical history including pain syndromes, mental health
- Sexual history
History that suggests a secondary cause includes:
- Onset after 25 years old
- Abnormal uterine bleeding
- Non-midline pelvic pain
- Absence of associated symptoms during menstruation
- Presence of dyspareunia or dyschezia
- Progression in severity
A physical exam is typically performed for adult patients to rule out secondary causes. For adolescent patients who are not sexually active, a suggestive history is adequate unless there is a poor response to treatment.
Risk Factors
Dysmenorrhea is associated with:
- Younger age
- Smoking
- Stress
- Family history (small predisposition)
Risk reduction occurs at first childbirth, with higher parity, and use of hormonal contraceptives.
Diagnosis
Criteria
Diagnosis of primary dysmenorrhea is made clinically as a diagnosis of exclusion.
Work-up
Laboratory testing is only indicated if secondary dysmenorrhea is suspected. This may include:
- Gonorrhea and chlamydia testing
- Urine testing for UTI
A TVUS may be indicated if an underlying anatomic abnormality is suspected.
Differential
See dysmenorrhea workup discussed separately.
Red Flags / Complications
Management
Non-pharmacological
Baseline interventions include:
- Exercise
- Heat therapy
Pharmacological / Interventional
Primary treatment and symptom management is through NSAIDs and/or hormonal therapy. In severe cases, a combination may be required.
NSAIDs
Initial treatment consist of either:
- Ibuprofen 400-600 mg q4-6h or 800 mg q8h; maximum daily dose of 2400 mg
- Naproxen sodium 550 mg initially, then 250 mg q6-8h; max daily dose of 1375 mg
NSAID should be started 1-2 days prior to expected onset of pain and continuously used. NSAIDs should be taken with food to minimize GI side effects.
If initial treatment is ineffective, mefenamic acid can be used:
- 500 mg initially, then 250 mg q6h; maximum daily dose of 1000 mg
Hormonal therapy (contraceptives)
All hormonal contraceptives reduce dysmenorrhea symptoms. Contraceptives are appropriate for patients including non-sexually active patients.
Patients with contraindications to estrogen (eg. migraine with aura) are limited to progestin-only options.