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, living ...

Finnish researchers found that hemoglobin levels that are within the normal range but at the lower end may be beneficial for health, particularly for glucose metabolism and cardiovascular health.