Why does hepatitis B cause jaundice?

Bilirubin is made when the body clears old red blood cells. The liver normally processes it for removal in bile. Hepatitis B may interfere with this process through liver inflammation, so bilirubin rises and can colour the whites of the eyes and skin yellow. Jaundice is a very common presentation of Hepatitis B. It is not specific to hepatitis B: blockage of bile flow, other liver conditions, some blood disorders, and certain medicines may also lead to jaundice.

New jaundice needs prompt medical assessment. Note any associated dark urine, pale stools, itching, nausea, vomiting, abdominal pain, fever, loss of appetite, or fatigue. Avoid alcohol and do not take new medicines, herbal remedies, or supplements without a clinician or pharmacist checking they are suitable. An assessment may include questions about symptoms and exposures, examination, and blood tests to clarify the cause and check liver function.

Seek urgent care for yellowing with confusion, unusual drowsiness, severe or increasing abdominal pain, persistent vomiting, fever with feeling very unwell, bleeding, vomiting blood, black stools, or fainting. Go promptly even if the yellowing is mild, because jaundice needs a cause identified and treated where needed.

Ask what could be causing the jaundice, whether hepatitis B testing is appropriate, what each liver blood test shows, which medicines to avoid, and whether close contacts need advice about protection.