Low Hemoglobin: Symptoms, Causes and Treatments

What Does Low Hemoglobin Mean?

Hemoglobin is the protein substance found in red blood cells, which is responsible for the transport of oxygen from the lungs to tissues and carbon dioxide from tissues back to lungs. It is made up of four protein molecules (globulin chains) that are joined together.

The normal adult hemoglobin (abbreviated Hb or Hgb) molecule is made up of two alpha-globulin chains and two beta-globulin chains. In fetus and babies, the beta chain is absent and the hemoglobin is made up of two alpha chains and two gamma chains. The beta chains replace the gamma chains as the infant grows.

Hemoglobin are also vital in maintaining the shape of a red blood cell. Red blood cells are naturally round with narrow centers similar to a donut without a hole in the middle. Abnormal hemoglobin structure can therefore alter the shape of red blood cells and disrupt the function and moiety through blood vessels.

Hemoglobin levels are usually expressed as the amount of hemoglobin in grams (gm) per deciliter (dL) of whole blood. The natural range for hemoglobin depends on various factors such as age and gender.

A low hemoglobin level is also called anemia or low red blood count. When the red blood cells are lower than number it is called anemia and hemoglobin levels show this number. Anemia is diagnosed if the hemoglobin level is lower than 13.5g/dL in a man or less than 12g/dL in a woman.