Silent Signals: Are You Tired, or Is It Iron Deficiency?

Role of Hemoglobin and Oxygen Transport
The most common symptom of iron deficiency is extreme fatigue, which does not improve with rest. This occurs because your body lacks enough iron to produce hemoglobin, the protein that helps transport oxygen to tissues. When less oxygen reaches your muscles and tissues, you constantly feel lethargic, weak, and lacking energy for daily tasks.