Which of the following is a common symptom of iron deficiency?

• A. Anemia
• B. Nausea
• C. Hypertension
• D. Headache

Answer: (A)

Iron deficiency directly impairs hemoglobin synthesis, so the most consistent and common symptom is anemia. When there isn’t enough iron, red blood cells become smaller and paler (microcytic, hypochromic) and carry less oxygen to tissues. That reduced oxygen delivery manifests as fatigue, weakness, and pallor, which are hallmark signs of anemia. Other options aren’t as directly tied to iron lack: nausea isn’t a typical feature of iron deficiency itself, hypertension isn’t caused by low iron, and while headaches can occur with anemia, they’re not as specific or common as the overall anemia picture. The key takeaway is that iron deficiency most predictably presents as anemia due to diminished hemoglobin and oxygen transport.