Know about normal hemoglobin levels by age, including adults, children, and pregnant women. Understand the importance of healthy levels. Learn about the medical reasons of having low or high hemoglobin levels in your blood and how to increase low hemoglobin levels with diet or supplements. Hemoglobin is a protein in red blood cells that carries oxygen and carbon dioxide. Learn about normal hemoglobin levels by age and gender, causes and symptoms of low and high hemoglobin , and how to measure hemoglobin with blood tests.
