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Hemoglobin

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Hemoglobin, Hgb, Hemoglobin Cutoffs for Anemia

  • See Also
  1. Hematocrit
  2. Anemia
  3. Hemoglobinopathy
  4. Red Blood Cell Physiology
  • Physiology
  1. See Red Blood Cell Physiology
  2. Normal Hemoglobin is composed of 4 Protein-Heme complexes
    1. Two pairs of polypeptides (4 total)
      1. A pair of alpha chains are found in every normal Hemoglobin type
      2. A pair of other identical polypetides depending on Hemoglobin type (Gamma, Beta, Delta)
    2. Central iron-containing heme ring
      1. Attached to each of the 4 polypeptides
    3. Images
      1. hemoglobin.jpg
  3. Six types of normal Hemoglobin
    1. Embryonic
    2. Gower I
    3. Gower II
    4. Portland
    5. Fetal Hemoglobin (HbF): Alpha2-Gamma2
      1. Primary Hemoglobin in fetus
      2. Replaced by Adult Hemoglobin by age 6-12 months
    6. Adult Hemoglobin (HbA): Alpha2-Beta2
    7. Adult Hemoglobin (HbA2): Alpha2-Delta2
  4. Abnormal Hemoglobins
    1. See Hemoglobinopathy
    2. Sickle Cell Disease (Hemoglobin S)
      1. Sickle Cell Trait
      2. Sickle Cell Anemia
      3. Combination disorders (Sickle B Thalassemia, Sickle C Disease, Sickle D Disease)
    3. Thalassemia
      1. Alpha Thalassemia (Hemoglobin Bart's: Gamma4)
      2. Beta Thalassemia (Hemoglobin H: Beta4)
        1. Beta Thalassemia minor
        2. Beta Thalassemia Major
    4. Unstable Hemoglobins
      1. Congenital Heinz body Hemolytic Anemia
      2. Methemoglobinemia
  • Interpretation
  • Normal Values per age (-2 to +2 S.D)
  1. Birth: 13.5 to 24.0 g/dl (mean 16.5 g/dl)
  2. Age <1 month: 10.0 to 20.0 g/dl (mean 13.9 g/dl)
  3. Age 1-2 months: 10.0 to 18.0 g/dl (mean 11.2 g/dl)
  4. Age 2-6 months: 9.5 to 14.0 g/dl (mean 12.6 g/dl)
  5. Age 0.5 to 2 years: 10.5 to 13.5 g/dl (mean 12.0 g/dl)
  6. Age 2 to 6 years: 11.5 to 13.5 g/dl (mean 12.5 g/dl)
  7. Age 6-12 years: 11.5 to 15.5 g/dl (mean 13.5)
  8. Male
    1. Age 12-18 years: 13.0 to 16.0 g/dl (mean 14.5 g/dl)
    2. Age >18 years: 13.6 to 17.7 g/dl (mean 15.5 g/dl)
  9. Female
    1. Age 12-18 years: 12.0 to 16.0 g/dl (mean 14.0 g/dl)
    2. Age >18 years: 12.1 to 15.1 g/dl (mean 14.0 g/dl)
  • Interpretation
  • Anemia Cut-offs
  1. Men and adolescent males
    1. Age 12-18 years: <13 g/dl (mean 14.5 g/dl)
    2. Age >18 years: <13 g/dl (WHO) or <13.5 g/dl (CDC)
  2. Women and adolescent girls (Non-pregnant, non-lactating)
    1. Age 12-18 years: <12 g/dl (mean 14 g/dl)
    2. Age >18 years: <12 g/dl (WHO and CDC)
  3. Women in Pregnancy (CDC Guidelines <5th percentile)
    1. First Trimester: <11.0 g/dl
    2. Second Trimester: <10.5 g/dl
    3. Third Trimester: <11.0 g/dl
  4. Children (CDC Guidelines <5th percentile)
    1. Age 1-2 years: <10.5 g/dl
    2. Age 2-6 years: <11.5 g/dl (mean 12.5 g/dl)
    3. Age 6-12 years: <11.5 g/dl (mean 13.5 g/dl)
  5. Infants (2 S.D. below mean)
    1. Term (cord blood): <13.5 g/dl (mean 16.5 g/dl)
    2. Newborn (1-3 days): <14.5 g/dl (mean 18.5 g/dl)
    3. Age 2 weeks: <13.4 g/dl (mean 16.6 g/dl)
    4. Age 1 month: <10.7 g/dl (mean 13.9 g/dl)
    5. Age 2 months: <9.4 g/dl (mean 11.2 g/dl)
    6. Age 6 months: <10.5 g/dl (mean 12 g/dl)
  • Causes
  • Increased Hemoglobin
  1. Polycythemia Vera
  2. Vigorous Exercise
  3. High altitude
  • Causes
  • Decreased Hemoglobin
  1. See Anemia
  • References
  1. Behrman (2000) Nelson Pediatrics, Saunders, p. 1462
  2. Flerlage (2015) Harriet Lane Handbook, Mosby, p. 305
  3. (1998) MMWR Morb Mortal Wkly Rep 47:1-29 [PubMed]
    1. http://www.cdc.gov/mmwr/pdf/rr/rr4703.pdf
  4. Short (2013) Am Fam Physician 87(2): 98-104 [PubMed]
  5. Wang (2016) Am Fam Physician 93(4): 270-8 [PubMed]