Hemoglobin

  • Medical Author:
    Charles Patrick Davis, MD, PhD

    Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

  • Medical Editor: William C. Shiel Jr., MD, FACP, FACR
    William C. Shiel Jr., MD, FACP, FACR

    William C. Shiel Jr., MD, FACP, FACR

    Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

What is the hemoglobin A1c test?

Hemoglobin A1c or glycosylated hemoglobin is a rough indication of blood sugar control in people with diabetes mellitus over the preceding 3 months. As more glucose (blood sugar) circulates in the blood on a daily basis, more glucose is bound to the circulating hemoglobin. Normal hemoglobin A1c levels range between 4% to 5.9%. As this number reaches 6% or greater, it signifies poorer diabetes control.

A hemoglobin A1c of 6% roughly correlates with an average blood sugar level of 135 mg/dL (milligrams per deciliters) over the previous 3 months. Each 1% increase in hemoglobin A1c above 6% represents an average blood sugar of approximately 35 mg/dL over 135 mg/dL. For example, a hemoglobin A1c measurement of 7% corresponds to an average blood sugar level of 170 mg/dL in the previous 3 months.

Reviewed on 11/4/2015
References
REFERENCES:

“Hemoglobin Concentration (Hb).” Medscape.

“Anemia of Chronic Disease and Renal Failure.” Medscape.

IMAGES:

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