What are the causes of menorrhagia (abnormally heavy or prolonged menstrual bleeding) in women of reproductive age?

Causes of Menorrhagia

Menorrhagia (heavy menstrual bleeding) is caused by structural abnormalities in approximately 50% of cases—most commonly uterine fibroids in women under 40 and endometrial polyps in women over 40—while the remaining cases stem from coagulopathies, ovulatory dysfunction, endometrial disorders, iatrogenic factors, or remain unclassified. 1, 2, 3

Structural Causes (PALM)

The PALM-COEIN classification system categorizes structural causes under the acronym PALM 1, 4:

• Polyps: Endometrial polyps are particularly common in women over 40 years of age and represent a frequent structural source of abnormal bleeding 4, 2
• Adenomyosis: A common cause in premenopausal women, frequently coexisting with fibroids and presenting with heavy bleeding, dysmenorrhea, and dyspareunia, typically affecting women in their 40s 5, 6
• Leiomyoma (Fibroids): The most common structural cause in women under 40 years of age, with submucous fibroids being particularly problematic for bleeding 4, 2, 3
• Malignancy and Hyperplasia: Endometrial cancer and hyperplasia must be excluded, especially in postmenopausal women or those with risk factors (obesity, diabetes, unopposed estrogen exposure, Lynch syndrome) 4, 3

Non-Structural Causes (COEIN)

• Coagulopathy: Up to 20% of women with heavy menstrual bleeding have an underlying inherited bleeding disorder, with von Willebrand disease being more common than many physicians realize 3, 7

  • Critical screening populations: All adolescents with menorrhagia, women with high-risk bleeding histories, and those who fail medical or surgical therapy should be screened for coagulopathies 3

• Ovulatory Dysfunction: Oligo-ovulation and anovulation cause irregular, heavy bleeding and should prompt evaluation for underlying causes including thyroid disease, hyperprolactinemia, hyperandrogenic conditions (PCOS), hypothalamic dysfunction, and premature ovarian failure 1

• Endometrial: Primary endometrial disorders involving molecular deficiencies in the regulation of endometrial hemostasis, including abnormal prostaglandin levels or fibrinolytic system dysfunction 4, 8

• Iatrogenic: Approximately 70% of women on anticoagulation therapy experience heavy menstrual bleeding 4

  • Oral anticoagulants (particularly factor Xa inhibitors like rivaroxaban) cause abnormal uterine bleeding in 9-14% of reproductive-age women, with rivaroxaban associated with prolonged bleeding (>8 days) in 27% of cases 1
  • Other medications include sex steroids, hypothalamic depressants, digitalis, phenytoin, and intrauterine contraceptive devices 3

• Not Yet Classified: Other causes that don't fit the above categories 1, 4

Critical Diagnostic Considerations

Always rule out pregnancy first in any reproductive-age woman with abnormal bleeding—this is the most important initial step 4, 5, 3

Age-specific diagnostic priorities:

• Reproductive age: Consider pregnancy complications until proven otherwise 3
• Adolescents: Attribute menorrhagia to coagulopathy until proven otherwise 3
• Perimenopausal/postmenopausal: Consider malignancy until proven otherwise 3

Common Pitfalls to Avoid

• In approximately 50% of menorrhagia cases, no pathology is found at hysterectomy, representing dysfunctional uterine bleeding by exclusion 2, 8
• Women on anticoagulation require special consideration, as abnormal uterine bleeding occurs in 9-14% of the general female population but is exacerbated by anticoagulants 1
• Coagulation disorders are underdiagnosed—maintain high clinical suspicion in adolescents and women with treatment-refractory bleeding 3, 7