Overview
A routine blood test, a screening before donating blood, or a check during pregnancy is how many people first learn they have hepatitis B. Often there were no symptoms leading up to it at all, which is part of what makes this virus so easy to carry for years without knowing.
Disease Summary
- Category
- Infectious Disease
- Cause
- Hepatitis B virus (HBV), which infects and inflames the liver
- Transmission
- Contact with infected blood or body fluids, including from mother to child during birth, sexual contact, and unsafe injections or exposure to sharp instruments
- Body System
- Liver
- Preventable
- Yes
- Curable
- No
Symptoms
Common Symptoms
Many people with hepatitis B, especially children, have no symptoms at all. When symptoms do appear, they typically include the following.
Fatigue
A persistent, unusual tiredness is one of the most common symptoms when they occur.
Loss of Appetite and Nausea
Reduced appetite, nausea, and occasional vomiting can develop, particularly in acute infection.
Abdominal Discomfort
A dull ache or discomfort, usually in the upper right side of the abdomen, near the liver.
Dark Urine
A noticeable change in urine colour can be an early sign of liver involvement.
Jaundice
Yellowing of the skin or eyes usually appears later, once the liver is more significantly affected.
Danger Signs
Seek urgent medical attention if any of the following develop.
Yellowing of the Skin or Eyes That Is Worsening
Rapidly worsening jaundice can indicate the liver is struggling to keep up and needs urgent assessment.
Confusion or Difficulty Staying Alert
Can indicate the liver is no longer clearing toxins properly, a serious complication requiring emergency care.
Severe Abdominal Pain or Swelling
May indicate significant liver inflammation or fluid buildup and should be assessed promptly.
Easy Bruising or Bleeding
Can indicate the liver is struggling to produce proteins needed for normal blood clotting.
Diagnosis
Blood Test for Hepatitis B Surface Antigen (HBsAg)
The primary screening test. A positive result indicates a current infection, whether acute or chronic.
Additional Antibody Testing
Tests for other hepatitis B markers help determine whether an infection is new, ongoing, past, or whether someone is immune from vaccination.
Liver Function Tests
Blood tests that measure liver enzymes and function, helping assess how much the liver has been affected.
Laboratory Tests
Hepatitis B Surface Antigen (HBsAg)
A positive result confirms current infection with hepatitis B, whether acute or chronic.
Hepatitis B Core Antibody (Anti-HBc)
Helps distinguish a new infection from a past or ongoing one, depending on which antibody type is present.
Hepatitis B Surface Antibody (Anti-HBs)
Indicates immunity, either from a past infection that has cleared or from vaccination.
HBV DNA (Viral Load)
Measures how much virus is actively present, which helps guide treatment decisions for chronic infection.
Treatment
Supportive Care for Acute Infection
Most adults with acute hepatitis B recover fully on their own. Rest, good nutrition, and fluids support the body while it clears the virus, since there is no specific medicine for acute infection.
Antiviral Medication for Chronic Infection
For chronic hepatitis B, antiviral medications can suppress the virus and reduce liver damage, though they are not typically a cure and are not needed by everyone with chronic infection.
Prevention
Get vaccinated
The hepatitis B vaccine is safe and more than 95 percent effective, and is recommended as part of routine childhood immunisation.
Ensure newborns receive the birth-dose vaccine
A dose given within 24 hours of birth is one of the most effective ways to prevent mother-to-child transmission, a major route of infection in high-burden regions.
Practise safe injection and blood safety measures
Avoiding the reuse of needles or syringes, and ensuring blood for transfusion is properly screened, prevents transmission.
Practise safer sex
Using condoms and knowing a partner’s hepatitis B status reduces the risk of sexual transmission.
Risk Factors
Higher Risk of Chronic Infection
Age at infection is the strongest factor in whether hepatitis B becomes a lifelong infection.
- Infants infected at birth, particularly from an infected mother
- Children infected before the age of 5
Increased Chance of Infection
These groups have a higher chance of exposure to hepatitis B.
- People born in or with family from regions where hepatitis B is common
- Healthcare workers and others regularly exposed to blood
- People with multiple sexual partners or a partner with hepatitis B
Exposure Factors
Situations that increase the risk of exposure.
- Sharing needles or injection equipment
- Receiving unscreened blood products or unsterile medical or dental procedures
Complications
Cirrhosis
Long-term liver inflammation can lead to scarring of the liver, which impairs its ability to function.
Liver Cancer (Hepatocellular Carcinoma)
Chronic hepatitis B significantly increases the lifetime risk of liver cancer, even in people without cirrhosis.
Liver Failure
In severe cases, either acute or as an end stage of chronic disease, the liver can lose the ability to function, which is life-threatening.
When to Seek Medical Care
Yellowing of the Skin or Eyes
New or worsening jaundice should be assessed by a healthcare provider.
Confusion or Unusual Drowsiness
Can indicate the liver is struggling to clear toxins and needs urgent evaluation.
Severe Abdominal Pain or Swelling
May indicate significant liver involvement and should not be ignored.
Known Hepatitis B Exposure or Diagnosis Without Follow-Up Care
Anyone diagnosed with hepatitis B, or who has not been screened despite a known risk factor, should establish care with a doctor for ongoing monitoring.
Prognosis
Excellent for Most Adults with Acute Infection
About 95 percent of adults who become infected clear the virus completely within months and do not develop chronic infection.
More Likely to Become Lifelong When Infection Happens Early
Around 90 percent of infants infected at birth, and 30 to 50 percent of children infected before age 5, go on to live with chronic hepatitis B.
Manageable With Long-Term Monitoring
For people with chronic hepatitis B, regular monitoring and, when needed, antiviral treatment can significantly reduce the risk of serious liver disease.
Differential Diagnosis
Hepatitis A
Also causes liver inflammation and jaundice, but spreads through contaminated food or water rather than blood or body fluids, and does not become chronic.
Hepatitis C
Another blood-borne virus that can cause chronic liver infection, often distinguished from hepatitis B through specific blood testing.
Malaria
Severe malaria can also cause jaundice and abdominal symptoms in the same regions, and should be considered when hepatitis B testing is not yet available.
References
World Health Organization (WHO)
World Health Organization fact sheet on hepatitis B transmission, symptoms, diagnosis, treatment, and prevention.
Centers for Disease Control and Prevention (CDC)
Public information on hepatitis B symptoms, spread, prevention, vaccination, and treatment.
CDC Clinical Overview of Hepatitis B
Clinical guidance for healthcare providers on hepatitis B risk factors, natural history, and chronic infection risk by age.
Frequently Asked Questions
Can hepatitis B be cured?
Acute hepatitis B usually clears on its own in adults. Chronic hepatitis B is generally not curable, but antiviral treatment and regular monitoring can control the virus and significantly reduce the risk of serious liver disease.
How is hepatitis B spread?
Mainly through contact with infected blood or body fluids, including from mother to child during birth, sexual contact, and sharing needles or unsterile medical equipment. It is not spread through casual contact, sharing food, or coughing.
Can I have hepatitis B without knowing it?
Yes. Many people, especially children, have no symptoms at all and only discover the infection through a blood test, such as routine screening or a check during pregnancy.
Is the hepatitis B vaccine safe?
Yes. It has been used safely for decades and is more than 95 percent effective at preventing infection.