hypochrome

Hypochrome is an adjective used in biology, medicine, and histology to describe cells, tissues, or structures that stain less intensely with standard dyes than is typical. The term comes from the Greek hypo- meaning under or below, and chroma meaning color. In hematology and cytology, hypochrome most often refers to red blood cells that have lower than normal hemoglobin content, resulting in increased central pallor on a blood smear.

In red blood cells, hypochromia is commonly assessed by indices such as mean corpuscular hemoglobin concentration (MCHC). Hypochromic erythrocytes are frequently seen in microcytic anemias, where reduced hemoglobin content is a hallmark. Iron deficiency is the most frequent cause, but hypochromia can also be observed in sideroblastic anemia and some thalassemias, and may appear in anemia of chronic disease at later stages. The presence and degree of hypochromia help guide diagnostic evaluation and treatment planning.

Outside hematology, hypochrome describes cells or tissues that stain weakly relative to normal under specific histological stains, reflecting lower pigment content or dye uptake. The term is often contrasted with hyperchromic, which denotes increased staining intensity. Hypochromia and hypochrome provide descriptive, context-dependent markers of cellular composition and pathology, rather than independent diagnostic tests.