Symptoms of acute hepatitis B
It can take 2 or 3 months for acute hepatitis B to develop after you come into contact with the virus. Any symptoms usually last between 1 and 6 weeks. Some people do not notice any symptoms. The most common symptoms are a bit like mild flu. They can include:
- Generally feeling unwell
- Losing your appetite
- Feeling or being sick
- A slightly raised temperature
- Pain in the top right of your tummy, under your ribs
- A yellow colour to your skin or eyes (jaundice)
- Dark coloured pee
- Pale coloured poo
If you notice any of these things, tell a doctor. They will do tests to find out what is wrong.
Tests for acute hepatitis B
If your doctor thinks you might have acute hepatitis B they will do blood tests. These look for parts of the virus and check how your immune system is responding.
There are 2 main tests your doctor will look at.
Hepatitis B surface antigen (HBsAg)
- The surface antigen is part of the outside of the virus. If this test is positive or reactive it means you currently have the virus in your blood.
- About 1 in 10 people with acute hepatitis B test negative or non-reactive. This is a sign their immune system is fighting the virus.
Antibody against the core antigen (Anti-HBc or HBcAb)
- Your immune system makes this antibody if it has ever come into contact with the hepatitis B virus. If this test is positive or reactive it means you have hepatitis B now or have had it in the past.
- Some doctors also check the exact type of antibody you have. If your antibodies are type M (immunoglobulin M or IgM) it is more likely you have an acute infection.
To check that your immune system has cleared the virus, you should have another set of blood tests 6 months later.
There are other tests for hepatitis B that you might have. You can read more here.
Being diagnosed with an old infection
Blood tests can tell if you have had a hepatitis B infection in the past. Many people don’t feel unwell, so they are not tested and diagnosed with an acute infection at the time.
You might have had a test now because:
- You are pregnant
- You have donated blood
- You are being treated for another medical condition
- You were tested as part of a programme eg testing in A&Es
If you had a hepatitis B infection in the past, you don’t need any treatment. But it is important to tell all your doctors from now on that you have had hepatitis B.
Protecting other people
While you have acute hepatitis B, the virus can be passed on to others. So it’s important to help protect people.
Let people close to you, like those you live with, know what is happening. You could ask them to read this page to help explain. They can get a free test and vaccine from their GP to help protect them. Read more about hepatitis B vaccines.
The virus is passed on through blood and body fluids. It’s important to:
- Clean and cover cuts and scratches with a plaster, and clean up any spilt blood with a bleach solution
- Use barrier protection if you have sex eg a condom
- Not share anything that can get blood on it, such as razors, toothbrushes, or needles
If there is a risk of the virus getting passed on at work, you might need to tell your employer. For example if you work in healthcare. They can help you follow safe working practices. Read advice from the Health and Safety Executive.
Read more about how hepatitis B is passed on and who is at risk.
Treating acute hepatitis B
Acute hepatitis B almost always clears up by itself without causing any problems. More than 95 out of every 100 people will fight off the virus without any treatment.
There are things you can do to help your liver recover. They can also help you feel better if you have symptoms. You should:
- Get lots of rest
- Drink plenty of water
- Avoid alcohol
- Eat well, with lots of fruit and vegetables
Medicines like paracetamol can help with any symptoms. Check with your doctor before taking them. Your liver processes medicines, so you might need to take less than usual.
In a very small number of people, acute hepatitis B can cause serious liver damage. This is called fulminant hepatitis B. Tell your doctor if you still feel unwell after 4 weeks. The most important symptom to be aware of is jaundice, you might notice:
- a yellow colour to your skin or eyes
- dark coloured pee
- pale coloured poo
Fulminant hepatitis B can be treated with antiviral medicine. In very rare cases, some people need to have a liver transplant.
Stopping hepatitis B coming back (reactivation)
When you fight off the hepatitis B virus, a very small part gets left behind in your liver. It doesn’t show up in blood tests. Usually it just sits there for the rest of your life. It does not harm your liver or make you unwell.
Treatments that make your immune system work less well can lead to hepatitis B coming back. This includes:
- Some types of chemotherapy for cancer
- Immunosuppressant medicines
- That you take after an organ transplant.
- That you take for some conditions eg autoimmune hepatitis, rheumatoid arthritis, multiple sclerosis, inflammatory bowel disease or certain skin conditions.
Tell all your doctors that you have had hepatitis B. They can make sure any treatments don’t lead to it coming back.
These treatments are for serious health problems. So most people have the treatment and also have treatment that stops hepatitis B coming back. Your doctor might call this prophylaxis (say pro-fi-lack-sis). Your doctor will talk to you about the options in your case.
The treatment to control hepatitis B depends on the situation. Usually you take a daily antiviral tablet. This starts around the same time as your immune-lowering treatment. You might need to take the antiviral for longer than your treatment for the other condition.
Next
Tests
Download the factsheet
Published April 2024