Anemia is characterized by low levels of which component?

Anemia is primarily characterized by low levels of red blood cells (RBCs), specifically the hemoglobin found within them. Hemoglobin is the protein in red blood cells that carries oxygen from the lungs to the body's tissues. When hemoglobin levels are below normal, it results in a decreased capacity for blood to carry oxygen, leading to symptoms such as fatigue, weakness, and pallor.

This condition can arise from a variety of causes, including nutritional deficiencies, chronic diseases, or bone marrow disorders, all of which affect the production or lifespan of red blood cells. By understanding that anemia involves a deficiency in red blood cells and their hemoglobin content, one can appreciate the impact this condition has on overall health and the importance of monitoring hemoglobin levels in patients.