Iron-deficiency anemia

Audience: Patients and providers
Status: Clinical guide · patient + provider
Last updated: 2026-03-27

1. Clinical overview

Iron-deficiency anemia is reduced hemoglobin caused by depleted iron stores, and effective care depends on both repletion and identifying why iron loss or malabsorption occurred.

2. Common causes and risk factors

GI blood loss, menstrual blood loss, malabsorption, pregnancy, bariatric surgery, and poor intake are common causes.
CKD, inflammatory disease, anticoagulation, and chronic NSAID use may complicate assessment.

3. Typical symptoms

Fatigue, dyspnea on exertion, pica, restless legs, dizziness, reduced exercise tolerance, and sometimes brittle nails or glossitis.

4. Diagnosis and evaluation

Confirm iron deficiency with ferritin and iron studies interpreted in clinical context.
Evaluate bleeding risk, menstrual history, GI symptoms, diet, and malabsorption risk.
Distinguish iron deficiency from anemia of inflammation, B12 deficiency, and mixed etiologies.

5. Treatment (non-pharmacologic)

Improve dietary iron intake and pair iron-rich foods with vitamin C-containing foods when feasible.
Address ongoing blood loss or absorption barriers rather than relying on supplementation alone.

6. Treatment (pharmacologic)

Oral iron commonly uses ferrous sulfate, ferrous gluconate, or ferrous fumarate in stable patients able to tolerate it.
Alternate-day or lower-frequency dosing may improve tolerance and absorption for oral iron.
IV formulations such as iron sucrose, ferric carboxymaltose, ferumoxytol, or ferric derisomaltose are useful when oral therapy fails, is poorly tolerated, or rapid repletion is needed.

7. Monitoring and follow-up

Monitor reticulocyte or hemoglobin response, ferritin recovery, and tolerance.
Continue replacement long enough to replete stores, not just normalize hemoglobin.

8. Practical counseling points

Iron commonly causes dark stools and GI discomfort; review this upfront to improve adherence.
Separate oral iron from major absorption inhibitors when possible.
Lack of response should trigger reassessment, not indefinite continuation of ineffective dosing.

9. Red flags and escalation

Escalate for severe symptomatic anemia, hemodynamic instability, overt GI bleeding, or suspected malignancy.
Consider GI, hematology, or gynecology evaluation when the source is not clear or anemia recurs.

10. Guideline references

Hematology guidance for iron deficiency evaluation and treatment.
Gastroenterology society recommendations for IDA workup.
Obstetric and CKD guidance where relevant to population-specific care.

Note: Educational guide only; not a substitute for individualized medical care.