What is anemia characterized by?

Anemia is defined as a condition where there is a deficiency in the number or quality of red blood cells or hemoglobin in the blood, leading to reduced oxygen transport throughout the body. This deficiency can arise from various factors, including inadequate red blood cell production, increased destruction of red blood cells, or significant blood loss.

In anemia, the reduced red blood cell count can result in symptoms such as fatigue, pallor, shortness of breath, and a general lack of energy due to insufficient oxygen delivery to the tissues. Anemia can be caused by nutritional deficiencies, chronic diseases, bone marrow disorders, or genetic conditions, among other causes.

The other options do not relate to anemia. An excess of white blood cells indicates conditions like infections or leukemias, high levels of glucose in the blood are associated with diabetes, and elevated platelet counts can occur in conditions resulting in thrombocytosis but are unrelated to anemia. Thus, the defining characteristic of anemia is indeed the deficiency in the number or quality of red blood cells.