If you’ve just been diagnosed with hepatitis B after a routine blood test or following a blood donation, you may be feeling overwhelmed with information about this complicated infection and references to acute or chronic hepatitis B.

Here is an explanation of these two terms and what happens when you’re first infected with the hepatitis B virus (HBV). Hepatitis B is transmitted through blood and sexual fluids. It can be spread during unprotected sex, unsafe medical procedures, exposure to blood that enters your body through a cut,  or by sharing personal items such as razors, body jewelry or toothbrushes. Most commonly it is spread during childbirth when the mother is infected.

What is a chronic infection? When we’re infected as newborns or young children, our immature immune systems don’t notice or fight the virus and it travels to our liver and begins reproducing. With no opposition from our immune systems, a hepatitis B infection can continue for years. When a hepatitis B infection lasts longer than six months, it is considered a chronic or long-term infection. Most people with chronic hepatitis B were infected at birth or during early childhood. Immunization with the hepatitis B vaccine and hepatitis B immune globulin (HBIG), if available, within 12 to 24 hours of birth can break this mother-to-child infection cycle, but sometimes the birth dose of the hep B vaccine,  and more often HBIG, is not always available around the world. The birth dose must be followed with the remaining doses of the vaccine, often given as part of a combination vaccine according to schedule. Here are the U.S. and International hep B vaccine schedules. 

What is an acute infection? When we’re infected with HBV as healthy adults, about 90 percent of us are able to get rid of the infection within six months. It can take up to six months for our immune systems to generate antibodies and get rid of the infection in our liver. This short-term infection is called acute hepatitis B.

To determine if you have an acute or chronic infection, you must be tested for hepatitis B over a six-month period. The specific test that indicates if you are infected is the hepatitis B surface antigen (HBsAg) test. This antigen covers the surface of the virus and there are usually lots of HBsAg in your blood when you’re infected. If you test positive for HBsAg for longer than six months, it means you have a chronic hepatitis B infection.

But, if you no longer test positive (or “reactive”) for HBsAg after six months and you develop hepatitis B surface antibodies (HBsAb), then you have cleared hepatitis B after an “acute” infection. There are some additional blood tests that your doctor may order to get a better understanding of your infection, but not everyone has access to these tests. Some tests are rather expensive and they may still need to be repeated over time in order to confirm the diagnosis. Please be patient. The good news is that hepatitis B is not typically an emergency.

Here is more good news. If you are a healthy adult and are newly or acutely infected, know that your chances are good that the hepatitis B infection will go away on its own. It is rare that you require medication to get rid of the virus, your immune system does that for you.  A person with a new hepatitis B infection may not have any symptoms, or they may not be very notable. For example, you might feel more tired. About 70 percent of people newly-infected with hepatitis B never experience symptoms.

But, some people experience severe symptoms like jaundice (yellowing skin or eyes), severe nausea or vomiting, or a bloated stomach (unrelated to your weight), and they need to see a doctor immediately. If you have a new or acute infection, even these drastic symptoms may not necessarily mean that you need any form of treatment, but you will need to be monitored with additional tests to make sure your liver is safe. (Tests like ALT/AST, platelets and bilirubin.)

If you can’t confirm you were infected as a child, you will need to wait the six months to find out if you cleared your infection. Please be patient and do not panic, but remember you need to take precautions during this time to make sure you do not spread the infection to others. Practice safe sex (use a condom), and don’t share personal hygiene items that may have trace amounts of blood on them.

We also  suggest that family members, close household contacts and sexual partners get tested for hepatitis B and vaccinated if needed. Have them get the triple hepatitis B panel: HBsAg, HBcAb total and HBsAb. This will tell them if they have a current infection, if they recovered from a past infection, or if they are vulnerable and need to be vaccinated. This helpful chart will help with understanding blood tests.  There can be up to a nine-week period right after infection when they may not test positive for HBsAg even if they have been infected.  Repeat testing if unsure.