Anemia is an abnormally low level of which blood component?

• A. Platelets
• B. RBCs
• C. Plasma
• D. WBCs

Answer: (B)

Anemia is defined by an abnormally low level of red blood cells, or, more precisely, a low amount of hemoglobin within those cells, which reduces the blood’s ability to carry oxygen to tissues. Red blood cells use hemoglobin to pick up oxygen in the lungs and deliver it to every part of the body; when their numbers or hemoglobin content drop, tissues can’t get enough oxygen, leading to symptoms like fatigue and shortness of breath. Platelets are the cell type involved in stopping bleeding, not oxygen transport. Plasma is the liquid portion that carries nutrients and waste, but it isn’t what’s deficient in anemia. White blood cells protect against infection, and their levels aren’t what defines anemia. So the abnormal low component in anemia is the red blood cells (and their hemoglobin content).