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Hemoglobin

Definition

Hemoglobin is a protein in red blood cells that carries oxygen. A blood test can tell how much hemoglobin you have in your blood.

See also: Hemoglobin electrophoresis

Alternative Names

Hgb; Hb

How the test is performed

A blood sample is needed. For information on how this is done, see: Venipuncture

How to prepare for the test

No special preparation is necessary.

How the test will feel

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Normal Values

Normal results vary, but in general are:

  • Male: 13.8 to 17.2 gm/dL
  • Female: 12.1 to 15.1 gm/dL

Note: gm/dL = grams per deciliter

What abnormal results mean

Lower-than-normal hemoglobin may be due to:

Higher-than-normal hemoglobin may be due to:

Additional conditions under which the test may be performed:

What the risks are

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

  • Excessive bleeding
  • Fainting or feeling light-headed
  • Hematoma (blood accumulating under the skin)
  • Infection (a slight risk any time the skin is broken)

Encyclopedia content is provided as information only and not intended to replace the advice and instruction from your personal physician.