What is the main cause of hepatitis B?

Transmission can occur through sexual contact, shared needles or equipment, contact with blood, or from an infected parent to a baby around birth. The virus may cause a short illness or remain in the liver for a long time. Some people have no clear symptoms. When symptoms occur, they can include tiredness, nausea, abdominal discomfort, yellowing of the skin or eyes, and dark urine. Fatigue and dark urine can have many causes, so they do not by themselves confirm hepatitis B.

Arrange a medical assessment if you may have been exposed or have symptoms. Blood tests can identify hepatitis B markers and help show whether infection is recent or longstanding. A clinician may also check liver health with a Liver Function Test. Avoid sharing razors, toothbrushes, needles, or anything that may carry blood, and use protection during sex until you have personalised advice. Hepatitis B vaccination helps prevent infection and is worth discussing for household or sexual contacts and anyone with exposure risk.

Seek urgent medical help for severe confusion, unusual sleepiness, vomiting that prevents drinking, marked yellowing, or significant bleeding. Contact a clinician promptly after a possible blood or sexual exposure because time-sensitive preventive care may be available. Do not wait for symptoms if you are pregnant, have known liver disease, or live with someone who has hepatitis B.

Ask which hepatitis B tests you need, whether your liver needs monitoring, how to protect people close to you, and whether vaccination or specialist follow-up is appropriate.