What causes hepatitis A?

Hepatitis A is caused by a virus spread through contaminated food, water, hands, or close personal contact. The virus can enter the body when hygiene is poor or food is handled after contamination. It is not caused by stress, ordinary tiredness, or a cancer diagnosis, and symptoms alone cannot prove the source of an infection.

Exposure may occur through shared household contact, unsafe food or water, or sexual contact involving the mouth and the anal area. Some infected people have few or no symptoms. Others develop feeling generally unwell, nausea, reduced appetite, or dark urine as the liver becomes inflamed. The timing of exposure and test results helps a clinician assess what happened.

Wash hands with soap after toilet use and before preparing or eating food. If you may have been exposed, contact a healthcare professional promptly because advice can depend on when the exposure occurred. Blood tests may look for hepatitis A, and a liver function test can show how the liver is responding. Ask whether hepatitis A vaccination is appropriate for prevention.

Seek prompt assessment for yellow skin or eyes, dark urine with worsening illness, persistent vomiting, severe abdominal pain, confusion, or difficulty drinking. Early advice is particularly important for people with a pre-existing liver condition or a weakened immune system.

Ask where exposure may have occurred, which test confirms recent infection, how long precautions should continue, whether close contacts need advice, and how vaccination could reduce future risk.