What should you know about hepatitis A antibody IgM?

IgM is an antibody the immune system produces early in an infection. A positive hepatitis A IgM result may support recent hepatitis A, especially when symptoms and liver blood tests fit. It is not interpreted in isolation: timing, the laboratory method, previous results, vaccination history, and other causes of abnormal liver tests can matter. A result can be unexpected or unclear, and a clinician may repeat or confirm testing. Symptoms can include feeling generally unwell, nausea, loss of appetite, dark urine, fever, or yellowing of the skin and eyes. A symptom page cannot determine the cause.

Contact the clinician who ordered the test to review the result and your symptoms. They may check a Liver Function Test, review medicines and supplements, and discuss ways to reduce spread through careful handwashing and avoiding food preparation for others while unwell. Rest and drink fluids as tolerated. Do not donate blood or share personal items without receiving specific medical advice. Hepatitis A Vaccination is preventive; it is not a treatment for an established infection.

Get urgent care if you cannot keep fluids down, become confused or unusually drowsy, faint, develop severe abdominal pain, or pass very little urine. Seek prompt assessment for worsening jaundice, rapidly increasing weakness, or dark urine with significant illness. A test result should not delay help when symptoms are severe.

Ask what the IgM result means in relation to the date symptoms began, whether another blood test is needed, how long precautions should continue, and whether close contacts need advice. Mention every medicine, supplement, recent vaccine, and possible food or water exposure.