Liver function tests (LFTs) 


Liver function tests are blood tests that measure a range of chemical substances that relate to the way the liver works.

Why would I need an LFT blood test?

LFTs are a set of blood tests that give a 'snapshot' of the current state of your liver. Abnormal liver functions are shown by how much the substances tested for fall below or rise above the normal range.

Results show if your liver is under strain, infected, inflamed or damaged, and to what extent.

Need to know

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.

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The Harley Street Clinic

The Harley Street Clinic

35 Weymouth Street W1G 8BJ London
The Princess Grace Hospital

The Princess Grace Hospital

42-52 Nottingham Place W1U 5NY London
The Shard Outpatients

The Shard Outpatients

The Shard, 32 St Thomas Street SE1 9BS London

This content is intended for general information only and does not replace the need for personal advice from a qualified health professional.