Medical case narrative
Iron without anemia — the ferritin nobody checked
What happened
A 40-year-old woman lived six years with fatigue and broken sleep. Her hemoglobin was 137 g/L — normal. By the headline number, she was not anemic, and the search could have stopped there.
What it looked like
Exhaustion and fragmented sleep with "normal bloods."
What the labs found
Her ferritin — stored iron — was 5.4 µg/L. Profoundly low, hiding behind a normal hemoglobin.
What changed
Given IV iron (ferric carboxymaltose 500 mg) at months 14, 18, and 25, all her symptoms disappeared within four weeks each time — and returned as her ferritin drifted down toward ~100 µg/L. A second woman in the same report, 55, with ten years of restless legs and a ferritin of 27, improved gradually as oral iron brought her ferritin to 100 over twelve months, and relapsed when she stopped. One honest confounder: both women were also receiving thyroid treatment, and this entry won't hide that.
The test that told the story
Ferritin — checked even when hemoglobin is normal.
Sources: Clinical Case Reports (Wiley), PubMed Central version of the same article.