Hepatitis B
Hepatitis B is a vaccine-preventable liver infection caused by HBV that can be short-term or chronic and may lead to cirrhosis or liver cancer.
What hepatitis B is
Hepatitis B is a liver infection caused by hepatitis B virus, often shortened to HBV. Some infections are acute and clear from the body, while others become chronic. Chronic hepatitis B can quietly damage the liver for years, which is why vaccination, screening, and long-term care matter.
How HBV spreads
HBV spreads through infected blood and certain body fluids. Transmission can happen during birth, sex, sharing needles or injection equipment, unsafe medical or tattooing practices, or household exposure to blood through items such as razors or toothbrushes. It does not spread through casual contact, coughing, sneezing, hugging, or sharing food.
Symptoms
Many people have no symptoms at first. When symptoms occur, they can include fever, fatigue, loss of appetite, nausea, vomiting, abdominal pain, dark urine, pale stools, joint pain, and jaundice. Symptoms alone cannot tell whether infection is acute, chronic, or caused by another hepatitis virus.
Acute and chronic infection
Adults who get hepatitis B often clear the infection, but infants and young children are much more likely to develop chronic infection. Chronic hepatitis B may feel silent until liver damage is advanced. Long-term complications can include cirrhosis, liver failure, and hepatocellular carcinoma, a type of liver cancer.
Screening and diagnosis
Hepatitis B is diagnosed with blood tests that look for viral markers and immune response. CDC recommends hepatitis B screening for adults at least once in a lifetime, with additional testing for people at higher risk or during pregnancy. Test results can show whether someone is infected, immune, susceptible, or needs follow-up.
Treatment
There is no specific medicine for most acute hepatitis B cases beyond supportive care. Chronic hepatitis B can be managed with monitoring and antiviral medicines when treatment criteria are met. Treatment may not cure HBV, but it can lower viral activity and reduce the risk of serious liver damage.
Vaccination and newborn prevention
Hepatitis B vaccine is the main prevention tool. Newborn protection is especially important because birth exposure can lead to chronic infection. When a pregnant person has HBV, timely newborn vaccination and hepatitis B immune globulin can greatly reduce the chance of transmission.
Public-health control
Hepatitis B control combines routine vaccination, prenatal screening, case reporting, harm-reduction services, safer healthcare practices, blood safety, and linkage to care. Because many people do not know they are infected, screening is a public-health tool as much as an individual medical test.
Why it matters
Hepatitis B matters because it can be both preventable and hidden. A person may feel well while carrying a virus that can spread to others or slowly injure the liver. That mix makes vaccination, testing, and ongoing care unusually powerful.