Hepatitis B tests

You do not need to do anything special before this test. A nurse or doctor will take a blood sample from a vein in your arm. No fasting or other preparation is needed. 

What the tests measure 

Unlike most single blood tests, hepatitis B testing uses a panel of different markers — proteins, antibodies, and viral genetic material — to build a complete picture of your infection status. Your doctor will usually request only the tests relevant to your situation. 

The main markers are: 

• HBsAg (hepatitis B surface antigen) – a protein on the surface of the virus itself. A positive result means the virus is present in your blood. It is the earliest sign of infection and can appear before symptoms develop. 
• Anti-HBs (hepatitis B surface antibody) – an antibody your body produces in response to the surface protein. A positive result means you are protected against hepatitis B, either through past infection or successful vaccination. 
• Anti-HBc IgM (hepatitis B core antibody, IgM) – the first antibody produced when you are newly infected. A positive result may point to a recent infection but may also be present alongside chronic infection. Further laboratory tests are needed to distinguish between recent and chronic, longstanding infection. 
• Anti-HBc total (hepatitis B core antibody, total) – detects both early (IgM) and later (IgG) core antibodies. A positive result can indicate acute infection, chronic infection, or past infection that has resolved. It usually remains detectable for life. 
• HBeAg (hepatitis B e‑antigen) – a protein released into the blood when the virus is actively multiplying. A positive result means the virus is very active and you are more likely to pass it to others. 
• Anti-HBe (hepatitis B e‑antibody) – an antibody that appears as HBeAg disappears. Its presence often signals that the virus is becoming less active. 
• HBV DNA – detects the genetic material of the virus directly. It is used mainly to monitor the effectiveness of antiviral treatment in chronic hepatitis B. 

What your results mean 

The meaning of hepatitis B results depends on which tests were done and how the results combine. The most common patterns are explained below. 

No current infection and no immunity 

If HBsAg, anti-HBs, and anti-HBc are all negative, you have not had hepatitis B before and are not currently protected against it. Your doctor may discuss whether you would benefit from vaccination. 

Protected through vaccination 

If anti-HBs is positive but anti-HBc is negative, this means you have protective antibodies from the hepatitis B vaccine. You are not infected and cannot pass the virus on. 

After vaccination, if your anti-HBs level is above 10 mIU/​mL, you are considered to have a good level of protection. Even if your level falls below this over time, you are generally still considered protected if you have completed the full vaccine course. 

Past infection that has now cleared 

If HBsAg is negative, anti-HBs is positive, and anti-HBc total is positive, this means you had hepatitis B in the past but your body has cleared the infection. You are now immune to reinfection. 

Early or acute (recent) infection 

If HBsAg is positive and anti-HBc IgM is positive, you may have had recent infection. The results of the other laboratory tests, alongside your clinical presentation will determine if you have had acute or chronic infection. This may mean the virus entered your body within the last few months. Most adults with an acute infection recover fully within a few weeks to months without needing specific treatment. 

If HBeAg is also positive during this stage, the virus is actively multiplying and you are more likely to pass it to others. Your doctor will advise you on how to protect those around you. 

Acute infection resolving 

As your body begins to fight the infection, HBeAg often disappears and anti-HBe becomes positive. This is called seroconversion and is a sign that the virus is becoming less active. HBsAg usually disappears next, followed by the appearance of anti-HBs, which confirms recovery. 

Chronic infection 

If HBsAg remains positive for more than six months, you have a chronic (long-term) hepatitis B infection. There are two forms: 

• Active chronic infection – HBsAg and HBeAg are both positive. The virus is actively replicating, which can cause ongoing liver inflammation and damage. Treatment is often recommended in this situation. 
• Inactive carrier state – HBsAg is positive but HBeAg is negative and anti-HBe is positive. The virus is present but not actively multiplying. Liver inflammation is low, but you can still pass the virus to others. Regular monitoring is important because the infection can reactivate. 

In some people with chronic hepatitis B, HBsAg eventually disappears on its own and anti-HBs appears. This is called functional cure and means the virus is effectively controlled, though it may remain in an inactive state in liver cells. 

HBV DNA testing is used to measure how much virus is in the blood and to track whether antiviral treatment is reducing viral activity. 

What happens next depends on your results and your clinical situation. 

If you have an acute infection, most adults recover without specific treatment. Your doctor will monitor your liver function and check that the infection has cleared. Rest and staying well hydrated are important while you recover. Alcohol should be avoided. 

If you have a chronic infection, your doctor will assess the level of liver inflammation and viral activity to decide whether antiviral treatment is needed. Regular monitoring – usually every six to twelve months – is typically recommended. Treatment can significantly reduce the risk of long-term complications such as cirrhosis or liver cancer. 

Prompt antiviral treatment is recommended for babies born to mothers with hepatitis B infection The development of the chronic infection after perinatal transmission can be prevented in over 90% of cases by appropriate vaccination, starting immediately at birth. Hepatitis B immunoglobulin is also recommended for babies at higher risk of infection. 

Hepatitis B is a notifiable infection in the UK. Your doctor is required to report a confirmed diagnosis to the UK Health Security Agency (UKHSA). This helps to identify outbreaks and protect others who may have been exposed. 

Close contacts and sexual partners who are not immune should be offered testing and vaccination. If you are pregnant and have hepatitis B, your baby will be offered immunoglobulin and vaccination at birth to prevent mother-to-baby transmission. 

• Timing of the test – HBsAg can be undetectable very early in infection before the body has produced it, or after an acute infection has fully resolved. Repeat testing may be needed if symptoms persist. 
• HBV strain variation – some strains of HBV, particularly those common in the Middle East and Asia, do not produce HBeAg. In these cases, a negative HBeAg result does not mean the virus is inactive or that you cannot pass it to others. HBV DNA testing gives a more reliable picture. 
• Immunosuppression – people with weakened immune systems may not produce the expected antibody responses, which can make results harder to interpret. 
• Reactivation – in people who have previously cleared the virus or are in the carrier state, the infection can reactivate – for example, if they receive immunosuppressive therapy. This is why baseline hepatitis B testing is recommended before certain treatments.

Your doctor may also request: 

• Liver blood tests (ALT, AST, GGT, bilirubin) – to assess liver inflammation and function 
• Hepatitis A virus antibodies – to check for co-infection or immunity 
• Hepatitis C virus antibodies – hepatitis C may need to be excluded, especially in people with risk factors for blood-borne infections 
• Acute viral hepatitis testing – a broader panel if the cause of hepatitis is not yet clear 

Hepatitis B is a liver infection caused by the hepatitis B virus. It spreads through contact with infected blood or body fluids. For many people it is a short-term illness, but in some it becomes a long-term (chronic) infection that can lead to serious liver complications. An effective vaccine is available. For more information, visit NHS: hepatitis B.