Liver function tests (LFTs) 

Before taking the sample, your consultant or nurse may clean the area of skin with an antiseptic wipe.

A syringe is used to remove a small amount of blood from your arm. You should only feel a pinprick as the blood is extracted. Pressure is applied using a cotton pad and a plaster may be put on the small wound. In some cases a tight band (tourniquet) may be put around your upper arm. This causes the vein to swell and makes it easier for a blood sample to be taken.

The sample can be taken by your consultant, or a nurse, or by other hospital staff, and the entire process will take only a few minutes.

As this is a very simple procedure, there is usually no preparation required. You may be asked to avoid eating or drinking anything except water for up to 12 hours before your liver function test. If you’re taking certain medication, you may also be advised to stop taking it for a while prior to the procedure.

It's important to follow the instructions you're given, as not doing so may affect the results of the test and you may be required to reschedule to do the procedure again.

Your consultant will explain the procedure and any instructions to you and answer any questions you may have.

Taking a sample of blood usually takes just a few minutes, with little or no pain, and you should be free to go immediately if you aren't feeling any after-effects like dizziness.

Your blood sample will then be sent to a laboratory for testing. Results should come back the same day or a few days later, although some tests will take a few weeks.

It's likely you will also need to have other tests to help specialists accurately assess your liver’s health in order to make a diagnosis. These may include a biopsy, endoscopy, and imaging tests.

Your consultant will talk to you about any tests that are required and answer any question or concerns you may have.