Anemia is NOT a Risk Factor for AUB—It's the Consequence
Anemia is not a risk factor for abnormal uterine bleeding (AUB); rather, AUB is a leading cause of iron deficiency anemia in women. The causal relationship flows in the opposite direction: excessive uterine bleeding depletes iron stores and causes anemia, not the other way around.
The Correct Causal Relationship
AUB causes anemia through chronic blood loss, making anemia a complication rather than a predisposing factor 1, 2. The evidence consistently demonstrates that:
- AUB is itself a leading cause of severe iron deficiency and iron deficiency anemia in women 3
- The primary management goal in AUB is preventing complications such as anemia, not treating anemia to prevent bleeding 1
- Women with AUB can develop critically severe anemia, with documented cases of hemoglobin dropping to 1.6 g/dL due to chronic bleeding from uterine pathology 3
Understanding the Pathophysiology
The mechanism is straightforward blood loss physiology:
- Heavy menstrual bleeding from structural causes (fibroids, adenomyosis, polyps) or functional causes (ovulatory dysfunction, coagulopathy) leads to excessive iron loss that exceeds dietary intake and body stores 4
- Chronic blood loss gradually depletes iron reserves, progressing from iron deficiency without anemia to frank iron deficiency anemia 2
- The severity of anemia correlates with the duration and volume of bleeding, not vice versa 3
Clinical Implications for Management
When approaching a patient with both AUB and anemia:
- Treat the underlying cause of AUB using hormonal therapies (combined oral contraceptives, progestogens), antifibrinolytics (tranexamic acid), NSAIDs, or surgical interventions depending on the etiology 1, 2
- Address anemia as a consequence through iron supplementation, blood transfusions in severe cases, and most importantly, controlling the bleeding source 3
- The degree of anemia helps guide treatment urgency but does not represent a risk factor for developing AUB 1
Common Pitfall to Avoid
Do not mistake the presence of anemia as a causative factor for AUB. While coagulopathies (such as von Willebrand disease) are true risk factors for AUB and may present with anemia, the anemia itself is not the risk factor—the underlying bleeding disorder is 5. Policymakers should prioritize minimizing diagnostic and treatment delays to reduce the risk of AUB-related anemia and the need for hysterectomy 2.