How can hepatitis B be transmitted?

Transmission can occur during sex, through shared needles or injecting equipment, from an infected mother to her baby around birth, or when contaminated blood reaches a cut, needlestick, or mucous membrane. Unsterile tattooing, piercing, or medical equipment can also carry risk. Ordinary contact such as hugging, sharing meals, coughing, or sitting nearby does not spread hepatitis B. Saliva alone is not the usual route, although blood in saliva can matter if it reaches broken skin or a mucous membrane.

Use condoms until a partner’s vaccination and immunity are confirmed, and never share needles, razors, toothbrushes, or equipment that may carry blood. Cover cuts and clean blood spills safely. Anyone with a possible exposure should contact a clinician quickly; [Hepatitis B Vaccination](/treatments/preventive-care-and-vaccination/hepatitis-b-vaccination/) and other post-exposure measures may be considered.

Seek prompt advice after a needlestick, sexual exposure, shared injection equipment, or contact with infected blood, particularly when vaccination is incomplete or unknown. Ask about testing and a [Liver Function Test](/treatments/diagnostics-and-screening/liver-function-test/). Urgent care is appropriate for yellow eyes, severe vomiting, confusion, or unusual bleeding. [Dark Urine](/symptoms/dark-urine/) and ongoing [Fatigue](/symptoms/fatigue/) should also be assessed.

Was the contact a meaningful exposure? Am I vaccinated or immune? Do I need immediate preventive treatment? When should I test, and how can I protect people at home?