What are they?

Hepatitis B virus tests are blood tests. They check for substances in your child's blood that show whether your child has hepatitis B now or had it in the past. The tests can help tell you if your child may have the disease long-term, how severe it is, and how easily it can be spread. They also can show if your child is protected from getting the disease.

If your child has the tests soon after being infected with hepatitis B, the results may show that your child doesn't have the disease even when they have it. The substances that show a hepatitis B infection can take weeks or months to form. They may not be in your child's blood yet.

Why are these tests done?

Your child may need testing if:

• Your child has symptoms of hepatitis.
• Your child may have been exposed to the hepatitis B virus. A newborn may be tested if the mother tested positive for the virus. Children may be tested if they or their parents come from an area where the hepatitis B virus is common.
• Your child may have been exposed through sexual contact or drug use.
• Your child has been in contact with an affected household.
• Your child has had other tests that point to liver problems.
• Your teen is pregnant.
• You or your doctor wants to know if your child is protected from getting the disease.

The tests also are done to help your doctor decide about your child's treatment and to see how well it's working.

How do you prepare for the tests?

You don't need to do anything before your child has these tests.

How is the test done?

A health professional uses a needle to take a blood sample, usually from the arm.

What happens after the tests?

Your child will probably be able to go home right away. And your child can go back to their usual activities right away.