What should you know about HBV, the hepatitis B virus?

When symptoms occur, they can include tiredness, nausea, reduced appetite, discomfort on the right side of the abdomen, yellowing of the eyes or skin, or dark urine. These features are presentations of hepatitis B, not proof that any one symptom identifies its cause. Learn more about [Hepatitis B](/conditions/hepatitis-b/), [Fatigue](/symptoms/fatigue/) and [Dark Urine](/symptoms/dark-urine/). Blood markers help show whether infection is current, past or prevented by vaccination.

Contact a healthcare professional promptly after a possible blood or sexual exposure; timing can affect which preventive options are considered. Ask about hepatitis B testing, a [Liver Function Test](/treatments/diagnostics-and-screening/liver-function-test/) and [Hepatitis B Vaccination](/treatments/preventive-care-and-vaccination/hepatitis-b-vaccination/). Until you receive advice, use barrier protection, do not share needles or personal items that may carry blood, and do not donate blood.

Seek urgent care for confusion, severe vomiting, yellowing with marked illness, unusual bleeding or rapidly worsening abdominal swelling. Arrange a prompt assessment for dark urine, pale stools or pronounced fatigue, especially after a known exposure or an abnormal hepatitis test.

Which HBV tests do I need, and when should they be repeated? Does my result suggest current infection, previous exposure or immunity? Do I need liver monitoring or treatment? Should my partner or household contacts be tested or vaccinated?