Hemoglobin is the protein which carries oxygen in the blood, and it is contained in red blood cells. Abnormalities of the hemoglobin value indicate defects in red blood cell homeostasis (balance). Both low and high values can indicate disease states.
Hemoglobin (varies with altitude):

Male: 13.8 to 17.2 gm/dl
Female: 12.1 to 15.1 gm/dl

Note: gm/dl = grams per deciliter