Hemoglobin A1c is a test that indicates the average level
of blood sugar over the past 2 to 3 months. People withdiabetesneed to have this test done regularly to see
whether their blood sugar levels have been staying within a target
Blood for a hemoglobin A1c test can be collected at home or
at your doctor's office.
Home testing. Home test kits for hemoglobin A1c
are available. Using the kit, you can use a lancet (a small needle) to take a
blood sample from a finger. Then, put a few drops of blood on a sample card.
Place the card in an envelope and send it to a lab for testing. The lab sends
the results of the test to you or your doctor.
Some doctors, particularly endocrinologists, have blood-analysis equipment in
their offices that can test hemoglobin A1c blood levels from a finger stick.
The doctor can then review the results during the
Laboratory testing. The most accurate measurement of
hemoglobin A1c level is done in commercial laboratories. These labs may be run
by local hospitals or large health clinics, or they may be independently owned.
Lab personnel check their equipment often, calibrate their machines on a
regular schedule, and are monitored by federal and state regulatory
authorities. A doctor's office sends the blood sample to the lab. How long it
takes to get results depends on the lab. You can have the test results reported
to you or your doctor.
Hemoglobin A1c test results show your average blood sugar
level over time. The result is reported as a percentage. Your goal is to keep
your hemoglobin A1c level as close to the normal level as possible. Studies
suggest that the lower the hemoglobin A1c level, the lower the incidence of
diabetic complications (eye, kidney, heart, blood vessel, and nerve disease).
The American Diabetes Association (ADA) recommends keeping the hemoglobin A1c
less than 7%. Some people may be able to achieve an even lower level of less
The table below compares hemoglobin A1c percentages with
average blood sugar levels over the previous few months.
Comparison of hemoglobin A1c and blood glucose levels
Hemoglobin A1c %
Average blood glucose (mg/dL)
Average blood glucose (mmol/L)
A1c levels for children and teens are different. For
children younger than 6 years old, the ADA recommends an A1c level from 7.5% to
8.5%. In children 6 to 12 years old, the recommended level is less than 8%. And
in teens, the recommended level is less than 7.5%.1
Results of hemoglobin A1c tests that are read at different labs
vary, but standardization among labs is improving. There could be differences
from one lab to another as great as half a percentage point. For example, if
your hemoglobin A1c at one lab is 8%, it may be 8.5% at another lab on the same
American Diabetes Association (2005). Care of children
and adolescents with type 1 diabetes.Diabetes Care,
Caroline Rea, RN, BS, MS
Susan Van Houten, RN, BSN, MBA
Pat Truman, MATC
Primary Medical Reviewer
Caroline S. Rhoads, MD - Internal Medicine
Specialist Medical Reviewer
Matthew I. Kim, MD - Endocrinology & Metabolism
September 24, 2008
WebMD Medical Reference from Healthwise
September 24, 2008
This information is not intended to replace the advice of a doctor.
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