Iron Deficiency and Desire to Smell Things
The desire to smell things is NOT a recognized symptom of iron deficiency; however, iron deficiency can cause itching (pruritus), pica (craving to eat non-food items), restless legs syndrome, and impaired olfactory function—but not an increased desire to smell things. 1, 2
What Iron Deficiency Actually Causes
Recognized Symptoms Related to Sensory Changes
Pica is a well-documented manifestation of iron deficiency, affecting 40-50% of patients, characterized by cravings to eat non-food substances like ice, dirt, or starch—not a desire to smell things. 2
Impaired olfactory function (reduced ability to smell) has been documented in iron deficiency anemia, with patients showing significantly lower threshold, discrimination, and identification scores on standardized olfactory testing. 3 This represents a decrease in smell function, not an increased desire to smell.
Generalized pruritus (itching without rash) is a recognized manifestation of iron deficiency, first described over 40 years ago, and can resolve completely shortly after iron replacement therapy begins. 1
Other Common Manifestations
Iron deficiency causes a spectrum of symptoms including:
- Fatigue, irritability, depression, and difficulty concentrating in both anemic and non-anemic iron deficiency 2, 4
- Restless legs syndrome affecting 32-40% of iron deficiency patients 2
- Exercise intolerance, dyspnea, and lightheadedness particularly in more severe cases 2, 5
- Hair loss as a protean manifestation 6
- Tongue sensations and oral manifestations recognized by the British Association of Dermatologists 7
Diagnostic Approach
Check complete blood count and ferritin levels in all patients with unexplained systemic symptoms, as recommended by multiple clinical guidelines. 1, 7
Important caveat: Ferritin is an acute-phase protein and may be falsely elevated during inflammation despite true iron deficiency. If clinical suspicion remains high with "normal" ferritin, check serum iron and total iron binding capacity. 1, 7
Diagnosis is confirmed by:
- Serum ferritin typically <30 ng/mL in individuals without inflammatory conditions 2
- Transferrin saturation <20% (calculated as iron/total iron binding capacity × 100) 2
Clinical Pitfall
Do not confuse pica (eating non-food items) with a desire to smell things—these are distinct phenomena. While pica is a classic manifestation of iron deficiency affecting up to half of patients, an increased desire to smell things is not documented in clinical guidelines or research literature as a symptom of iron metabolism disorders. 2, 1