Normal hemoglobin levels differ for men and women, with adult males having 13.8 to 17.2 g/dL and females having 12.1 to 15.1 g/dL. High hemoglobin levels can be caused by dehydration, smoking, or ...

Hemoglobin is a key protein found in red blood cells. Its main job is to carry oxygen from your lungs to the rest of your body. When hemoglobin levels drop, the body may not receive enough oxygen to ...