What is iron-deficiency anemia?
Anemia means hemoglobin is lower than normal, and iron-deficiency anemia is the most common form. Iron is a core building block of hemoglobin, so without enough of it, red blood cells become small and pale and tissues get less oxygen (Camaschella, 2015).
This article is general health information and is not a substitute for diagnosis or treatment. If symptoms persist, see a doctor.
What causes it, and what are the symptoms?
| Cause | Examples |
|---|---|
| Iron loss | Heavy periods, GI bleeding (ulcers, polyps, cancer), frequent blood donation |
| Higher needs | Pregnancy, growth spurts, intense training |
| Low intake or absorption | Crash diets, plant-heavy diets, gastric surgery, celiac disease, H. pylori |
Fatigue, dizziness, getting winded on stairs and pale skin are common. Brittle nails and cravings to chew ice (pica) can also occur. Blood tests show low hemoglobin and low ferritin, which reflects iron stores.
What should you know about treatment?
Treatment means replacing iron and finding the cause. Oral iron can cause constipation, heartburn and dark stools; recent research suggests taking it once a day or every other day may improve absorption and tolerance compared with multiple daily doses (Pasricha et al., 2021). Vitamin C boosts absorption, while tea, coffee and calcium reduce it. In men and postmenopausal women, iron deficiency calls for a workup, often including endoscopy, to rule out GI bleeding.
FAQ
- How long should I take iron?
- Usually for a few months after hemoglobin normalizes, to refill iron stores (ferritin). Ask your doctor about the right duration.
- Is every dizzy spell anemia?
- No. Dizziness has many causes, such as low blood pressure on standing or inner-ear problems, so a blood test is the way to check.
Sources reviewed: 2026-10-25
References
- Camaschella, C. (2015). Iron-deficiency anemia. New England Journal of Medicine, 372(19), 1832–1843.
- Pasricha, S.-R., Tye-Din, J., Muckenthaler, M. U., & Swinkels, D. W. (2021). Iron deficiency. The Lancet, 397(10270), 233–248.