What is the difference between hemoglobin and hematocrit?

Hemoglobin is a protein in red blood cells and hematocrit is a measurement of the amount of red blood cells as related to total blood cell count. Both hemoglobin and hematocrit are used to diagnose anemia. Both hemoglobin and hematocrit can be measured from standard blood tests, and both values are typically reported when a doctor orders a blood count.
The hematocrit (hct) is volume percentage of red blood cells in the blood and is expressed as a percentage. For example, a hematocrit of 25% means there are 25 milliliters of red blood cells in 100 milliliters of blood.
Why do doctors measure hemoglobin?
Hemoglobin (Hb) is a protein in red blood cells that contains an iron molecule. Hemoglobin carries oxygen from the lungs to the body's tissues and returns carbon dioxide from the tissues back to the lungs. The iron in hemoglobin plays an important role in maintaining the shape of the red blood cells.
Normal hemoglobin ranges depend on age and gender, and the “normal” range may vary by the specific test used. Normal hemoglobin levels are:
- Newborns: 17 to 22 gm/dL
- One (1) week of age: 15 to 20 gm/dL
- One (1) month of age: 11 to 15 gm/dL
- Children: 11 to 13 gm/dL
- Adult males: 14 to 18 gm/dL
- Adult women: 12 to 16 gm/dL
- Men after middle age: 12.4 to 14.9 gm/dL
- Women after middle age: 11.7 to 13.8 gm/dL
Low hemoglobin levels are referred to as anemia, or low red blood cell count. Causes of anemia include blood loss, nutritional deficiency, bone marrow disorders, bone marrow suppression by chemotherapy or radiation exposure, kidney failure, and abnormal hemoglobin structure, such as sickle cell anemia. High hemoglobin levels are often seen in people who live in high altitudes and in smokers. Other causes of high hemoglobin levels include dehydration, lung disease, cancer, bone marrow disorders (polycythemia vera), and “blood doping” by athletes.
Why do doctors measure hematocrit?
As with hemoglobin, normal hematocrit ranges depend on age and gender, and the “normal” range may vary by the specific test used. Normal hematocrit levels are:
- Newborns: 55% to 68%
- One (1) week of age: 47% to 65%
- One (1) month of age: 37% to 49%
- Three (3) months of age: 30% to 36%
- One (1) year of age: 29% to 41%
- Ten (10) years of age: 36% to 40%
- Adult males: 42% to 54%
- Adult women: 38% to 46%
Just as low hemoglobin levels signify anemia, a person with a low hematocrit percentage is also anemic. High hematocrit percentages are seen in the same populations that may have high hemoglobin levels.

QUESTION
Sickle cell disease is named after a farming tool. See AnswerTop Hemoglobin vs Hematocrit Related Articles
Anemia
Anemia is the condition of having less than the normal number of red blood cells or less than the normal quantity of hemoglobin in the blood. The oxygen-carrying capacity of the blood is, therefore, decreased. There are several types of anemia such as iron deficiency anemia (the most common type), sickle cell anemia, vitamin B12 anemia, pernicious anemia, and aplastic anemia. Symptoms of anemia may include fatigue, malaise, hair loss, palpitations, menstruation, and medications. Treatment for anemia includes treating the underlying cause for the condition. Iron supplements, vitamin B12 injections, and certain medications may also be necessary.Blood Disorders Quiz
Exactly what is sickle cell anemia? Learn about sickle cell and other diseases by testing your IQ with the Blood and Bleeding Disorders Quiz.Blood Basics Test Quiz
What do you know about blood? It runs all through your body, so educate yourself! Take this blood basics quiz to learn about human blood!Hematocrit Ranges (Normal, High, Low)
Hematocrit in the blood is the proportion of the blood that consists of red blood cells, by volume. A low hematocrit level may signal anemia, or other conditions such as loss of blood, nutritional deficiency, bone marrow problems, and abnormal hematocrit. High hematocrit levels may be due to chronic smoking, living at high altitudes, dehydration, or other conditions and diseases.Hemoglobin: Normal, High, Low Levels, Age & Gender
Hemoglobin is the oxygen-carrying protein molecule in the blood, specifically in the red blood cells. High hemoglobin count may be caused by dehydration, smoking, emphysema, tumors, or abuse of Epogen. Low levels of hemoglobin may be caused by anemia, blood loss, nutritional deficiency, bone marrow problems, chemotherapy, kidney failure, or sickle cell disease.Hemoglobin A1c Test
Hemoglobin A1c or HbA1c is a protein on the surface of red blood cells. The HbA1c test is used to monitor blood sugar levels in people with type 1 and type 2 diabetes over time. Normal HbA1c levels are 6% or less. HbA1c levels can be affected by insulin use, fasting, glucose intake (oral or IV), or a combination of these and other factors. High hemoglobin A1c levels in the blood increases the risk of microvascular complications, for example, diabetic neuropathy, eye, and kidney disease.Hemophilia Quiz
What happens within the body in a person who has hemophilia? Take this quiz to learn about this rare blood disorder.Paroxysmal Nocturnal Hemoglobinuria (PNH)
Paroxysmal nocturnal hemoglobinuria or PNH is a rare genetic disease in which there is an abnormal breakdown of red blood cells. Symptoms of PHN include irregular heartbeats, chest pain, abdominal pain, anemia, jaundice, seizures, and blood clots in the legs (DVTs). Treatment for PNH is directed toward the symptoms of the disease.
Pernicious Anemia
Pernicious anemia is a blood disorder in which the body does not make enough red blood cells due to a lack of vitamin B12 in the blood. Pernicious anemia can develop from a lack of a protein that helps the body absorb vitamin B12, not getting enough B12 in the diet, and certain intestinal conditions that interfere with the absorption of vitamin B12 such as Crohn's disease, celiac sprue, or ulcerative colitis. There is no cure for pernicious anemia, thus treatment is life-long.red blood cells
Red blood cells (RBCs), also known as erythrocytes, are cellular components of blood that give blood its characteristic red color. Red blood cells are used for transfusion in patients who have insufficient tissue oxygen because of active bleeding or symptomatic anemia, to increase the red blood cell count, hemoglobin level, and consequently, blood’s oxygen carrying capacity. Common side effects of red blood cells include hemolytic transfusion reactions that destroy red blood cells, feverish (febrile) non-hemolytic reactions, transfusion related acute lung injury (TRALI), transfusion-associated circulatory overload (TACO), allergic reactions, transfusion-associated graft-versus-host disease (TA-GVHD), transfusion-transmitted infections and septic reactions, and post-transfusion bruising (purpura). Consult your doctor if pregnant or breastfeeding.Sickle Cell Disease (Anemia)
Sickle cell anemia (sickle cell disease), a blood disease that shortens life expectancy, is caused by inherited abnormal hemoglobin. Symptoms of sickle cell anemia may include bacterial infections, painful swelling of the hands and feet, fever, leg ulcers, fatigue, anemia, eye damage, and lung and heart injury. Treatment for sickle cell anemia aims to manage and prevent the worst manifestations of the disease and focuses on therapies that block red blood cells from stacking together, which can lead to tissue and organ damage and pain.How Do You Fix Anemia?
Anemia describes a condition in which you have a low red blood cell count and low hemoglobin levels. This is a serious condition as red blood cells and hemoglobin carry oxygen to all your cells, allowing them to burn energy. If you’re anemic, you’ll likely feel fatigued and short of breath, lacking physical stamina. You may have heart problems and appear pale. Anemia is often a symptom of some other disease or condition, so treatment varies widely depending on the root cause.
What Is Hb H Disease?
Hemoglobin H (Hb H) disease is an inherited hemoglobin disorder in which three out of the four alpha-globin genes that are usually present are deleted or has a mutation that impairs alpha-globin chain production. This leads to an excess of beta-globin chains that are unstable, precipitate within the cell, and destroys the red blood cells. Hb H is a thalassemia-like syndrome defined by hemolysis and the production of ineffective red cells.