What should you know about hepatitis A virus Ab?

Ab is short for antibody. Your immune system makes antibodies after encountering an infection or, for some infections, after vaccination. A report may identify IgM, IgG, or total hepatitis A antibodies. IgM is used when recent infection is being considered, while IgG generally reflects immunity from a previous infection or vaccination. Total antibody results combine types and need the laboratory's explanation.

A positive antibody result does not automatically mean that you are currently infectious. A negative result does not explain every episode of nausea, loss of appetite, or feeling generally unwell. The timing of exposure and symptoms matters.

Give your clinician the full report rather than only the word positive or negative. They may compare the result with a liver function test, examination findings, and any recent exposure. Mention vaccination history, travel, shared meals, household illness, pregnancy, and medicines that could affect the liver. Until you receive advice, wash hands carefully after using the toilet and before preparing food, and avoid sharing food with others if infection is suspected.

If you have no immunity and a recent exposure, ask quickly whether hepatitis A vaccination is appropriate.

Seek prompt medical advice for yellowing of the eyes or skin, dark urine, ongoing vomiting, increasing abdominal pain, or inability to drink. Urgent assessment is needed for confusion, fainting, or severe dehydration. A known exposure deserves timely advice even without symptoms because preventive steps can be time-sensitive.

Ask which antibody was detected, whether the result suggests recent infection or immunity, whether repeat testing is needed, and whether your liver function test is reassuring. Also ask when normal food preparation, work, school, or close contact can resume.