What are the kinds of Hepatitis B blood tests?
There are four standard types of Hepatitis B blood tests:

• The Hepatitis B surface antigen (HBsAg) test
  • HBsAg is a marker on the protein coating of the hepatitis B virus
  • If found in high levels, these markers indicate the patient is currently infected with either acute or chronic hepatitis B and is able to infect others
• Hepatitis B core antibody (Anti-HBc) test
  • If positive, this test indicates the patient has had contact with the Hepatitis B virus; the test does not say whether the patient currently has an HBV infection or has had it in the past
  • Because interpretation is difficult, the anti-HBc test is used in combination with other tests.
• Hepatitis B surface antibody (anti-HBs) test
  • Presence of anti-HBs indicates the patient is now immune to subsequent Hepatitis B infections either due to the vaccination or due to a past HBV infection
  • The patient is non-infectious and cannot pass HBV to others
• IgM antibody to Hepatitis B core antigen (IgM anti-HBc)
  • If your doctor suspects you have an acute HBV infection, he will order this test
  • If positive, it indicates recent infection with HBV within the last 6 months (an acute infection, in other words)

How should I interpret my Hepatitis B blood test results? (from U.S. CDC)

Tests	Results	Interpretation
HBsAg anti-HBc anti-HBs	negative negative negative	Susceptible
HBsAg anti-HBc anti-HBs	negative negative positive with >10mIU/mL*	immune due to vaccination
HBsAg anti-HBc anti-HBs	negative positive positive	immune due to natural infection
HBsAg anti-HBc IgM anti-HBc anti-HBs	positive positive positive negative	newly infected
HBsAg anti-HBc IgM anti-HBc anti-HBs	positive positive negative negative	chronically infected
HBsAg anti-HBc anti-HBs	negative positive negative	four interpretations possible†

*Postvaccination testing, when it is recommended, should be done 1–2 months after the final dose.
†1. May be recovering from acute HBV infection.
 2. May be distantly immune and the test is not sensitive enough to detect a very low level of anti-HBs in serum.
 3. May be susceptible with a "false positive" anti-HBc.
 4. May be chronically infected and have an undetectable level of HBsAg present in the serum.