What are hepatitis A, B, and C blood tests?
Hepatitis is a general term that means inflammation of the
liver. Hepatitis A, B, and C are infections of the liver
caused by different viruses. The blood tests described here
help determine if hepatitis is caused by one of these
viruses.
Why are these tests done?
There are many possible causes of hepatitis. These blood
tests help determine if the liver inflammation is resulting
from infection with the hepatitis A, B, or C viruses.
How do I prepare for this test?
You don't need to take any special precautions or change
your diet before your have this test.
How is the test done?
A small amount of blood is taken from your arm with a
needle. The blood is collected in tubes and sent to a lab.
Having this test will take just a few minutes of your time.
There is no risk of getting AIDS, hepatitis, or any other
blood-borne disease from this test.
How will I get the test result?
Ask your health care provider when and how you will get the
result of your test.
What do the test results mean?
The results of the various hepatitis blood tests are
summarized below. These tests are divided into two groups.
The first group tests for the presence of the virus in the
blood. These are called antigen tests. The second group
tests for the body's reaction to the infection. These are
called antibody tests.
- Hepatitis A infection: A positive antigen test (called an
HAV or hepatitis A virus test) and a positive antibody
test (called an IgM anti-HAV antibody test) mean you
currently have an acute hepatitis A infection. If you
have had hepatitis in the past, your antigen test will be
negative, but the antibody test will be positive.
- Hepatitis B infection: A positive antigen test (called an
HbsAg or hepatitis B virus surface antigen test) and a
positive antibody test (called IgM anti-HBc or IgM
hepatitis B virus core antibody test) mean you currently
have an acute hepatitis B infection. If you have had
hepatitis for 6 months or more (chronic hepatitis), the
antigen test will be positive but the antibody test will
be negative. If you have had shots to protect you
against hepatitis, the antigen test will be negative and
the antibody test will be positive.
- Hepatitis C infection: A positive antibody test (called
an anti-HCV or antibody to hepatitis C virus test) means you
currently have an acute hepatitis C infection. To check for
chronic infection, tests are done to measure the amounts of
specific hepatitis C viral proteins (antigens) present in the
blood. If these tests remain positive for several months,
the disease is said to be chronic. In other words, your
body wasn't able to completely clear the infection.
What if my test result is not normal?
Test results are only one part of a larger picture that
takes into account your medical history and current health.
Sometimes a test needs to be repeated to check the first
result. Talk to your health care provider about your result
and ask questions.
If your test results are not normal, ask your health care
provider:
- if you need additional tests
- when you need to be tested again.
This content is reviewed periodically and is subject to
change as new health information becomes available. The
information is intended to inform and educate and is not a
replacement for medical evaluation, advice, diagnosis or
treatment by a healthcare professional.
Copyright © 2005 McKesson Corporation and/or one of its subsidiaries. All Rights Reserved.
This
information is approved and/or reviewed by U-M Health System providers
but it is not a tool for self-diagnosis or a substitute for medical
treatment. You should speak to your physician or make
an appointment to be seen if you have questions or concerns about
this information or your medical condition.