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Overview

What Is Hepatitis B?

Hepatitis B is an infection caused by the hepatitis B virus, or HBV, that primarily affects the liver. An acute infection is short term and may clear on its own, while a chronic infection lasts longer and can cause ongoing liver problems. Some people have no symptoms, so testing may be the only way to know they have this disease hepatitis infection.

How It Spreads (Transmission)

How Hepatitis B Spreads

HBV spreads through infected blood and certain body fluids, including during childbirth, sexual contact, sharing needles or injection equipment, needlestick injuries, and tattooing or piercing with unsterile equipment. It does not spread through casual contact, hugging, sharing food, or coughing. Understanding how do you get hepatitis b can help people choose safer practices and seek testing after a possible exposure.

  • Infants born to a parent with hepatitis B have a higher risk of infection during birth.
  • Household or sexual contacts of an infected person may be exposed to infected blood or body fluids.
  • People who share needles or other injection equipment have an increased risk of HBV transmission.
  • Healthcare and public-safety workers may face increased risk through contact with infected blood.
  • People from regions where HBV is common may have a higher likelihood of exposure.

Conditions It Can Cause

Conditions Hepatitis B Can Cause

  • Acute hepatitis B is a short-term infection that may cause liver inflammation and may resolve without becoming chronic.
  • Chronic hepatitis B is a long-term infection that can gradually damage the liver.
  • Cirrhosis is severe liver scarring that can develop after long-term liver injury.
  • Liver failure occurs when extensive damage prevents the liver from working properly.
  • Hepatocellular carcinoma, also called liver cancer, is a serious possible complication of chronic HBV infection.

The risk of long-term complications is greatest when infection becomes chronic, especially when it is not diagnosed or monitored. Regular medical follow-up can help assess liver health and manage the disease hepatitis may cause.

Symptoms

Hepatitis B Symptoms

Hepatitis B is often asymptomatic, especially in children. When symptoms and signs of hepatitis occur, they may include fatigue, fever, loss of appetite, nausea, vomiting, abdominal discomfort, dark urine, pale stools, joint pain, and jaundice.

Diagnosis

How Hepatitis B Is Diagnosed

Hepatitis B is diagnosed with blood tests, not symptoms alone. The main markers include hepatitis B surface antigen, surface antibody, and core antibody, which together help show whether HBV infection or immunity is present.

  • Testing can identify a current hepatitis B infection.
  • Testing can show immunity from vaccination.
  • Testing can show immunity after a past infection.
  • Testing can help indicate a recent exposure.
  • Testing can help determine whether infection may be chronic.

Clinicians may also order HBV DNA testing to measure viral genetic material and liver function tests when appropriate. Liver tests assess the effects of infection on the organ, but they do not detect the virus by themselves.

Prevention

Hepatitis B Prevention

An infant born to a person with hepatitis B may need both hepatitis B vaccine and hepatitis B immune globulin promptly after birth. Ask a clinician or local public health service for the current schedule and newborn protection guidance.

  • Use sterile injection and medical equipment.
  • Do not share needles or personal items that may contain blood, such as razors or toothbrushes.
  • Use barriers during sex when infection status is unknown.
  • Cover open wounds and avoid contact with another person’s blood.
  • Ensure tattoos and piercings are performed with sterile equipment.

After exposure

Ask about post-exposure prevention

Seek urgent medical advice after a significant blood or body-fluid exposure. Hepatitis B vaccine and hepatitis B immune globulin may help prevent infection when given promptly.

Affected Body System/Organ

Body System and Organ Affected by Hepatitis B

Hepatitis B is a viral infection that mainly affects the liver, which is part of the digestive system. It is caused by the hepatitis B virus (HBV). The liver has many important functions in the body. It helps digest nutrients, removes harmful substances from the blood, stores energy, and produces proteins that the body needs.

When the hepatitis B virus enters the body, it travels to the liver and infects liver cells. This can cause inflammation and prevent the liver from working normally. Some people may not have any symptoms, but others can experience tiredness, loss of appetite, nausea, abdominal pain, dark urine, and yellowing of the skin and eyes, called jaundice.

Hepatitis B can be a short-term infection, but sometimes it becomes chronic. Long-term hepatitis B can cause serious liver damage, including cirrhosis, liver failure, and liver cancer. Therefore, protecting the liver and preventing the spread of hepatitis B are very important for maintaining good health.

Diseases & Conditions

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