What should you know about liver function blood test fasting?

A liver panel measures several substances, including enzymes, bilirubin, albumin and sometimes clotting markers. The request may also include tests affected by recent food or drink, which is why a laboratory may give fasting instructions. Water is often treated differently from other drinks, but the laboratory should tell you exactly what is allowed. Do not assume that fasting is required or skip food without clear advice.

Tell the clinician if you have diabetes, become unwell when you do not eat, are pregnant, or take medicine that must be taken with food. The plan can be adjusted safely.

Check the appointment message and ask the laboratory what to eat, drink and take beforehand. If fasting is requested, follow the stated start time and bring any required medication information. Do not change prescribed medicines unless the ordering clinician tells you to. If you accidentally eat or drink something outside the instructions, tell the phlebotomist; they can decide whether the sample remains useful or should be rearranged. Results may be interpreted with other tests, including checks for Anaemia or Chronic Kidney Disease.

Fasting itself is not a reason to delay urgent care. Seek medical help for jaundice, confusion, fainting, vomiting blood, black stools, severe abdominal pain, or inability to keep fluids down. If fasting causes shakiness, sweating, weakness or confusion, follow your personal medical plan and seek advice, especially if you have diabetes.

Do I need to fast for the tests on my request? Is water allowed? Should I take my usual medicines? What should I do if I eat, feel unwell, or need to reschedule?