AST blood test in Chiswick

What the test measures

AST, or aspartate aminotransferase, is an enzyme involved in amino acid metabolism. It is found in liver cells, but also in heart and skeletal muscle, the kidneys and red blood cells. When any of these tissues are damaged, AST is released into the bloodstream, so a raised level is less specific to the liver than ALT.

AST is most useful when read with ALT. The ratio between the two can help suggest the likely cause of liver irritation, for example a higher AST than ALT is sometimes seen with alcohol-related liver changes or more advanced scarring. AST is also one of the values used to calculate the FIB-4 score, which estimates the likelihood of liver fibrosis. The price includes the blood sample taken at our Chiswick clinic, analysis at the Randox accredited laboratory, a review of your result with an Omnia practitioner and a GP feedback report on request.

Who it is for

• You drink alcohol regularly and want to check how your liver is affected.
• You have had a raised ALT and want to understand the pattern of your liver enzymes.
• You train intensively and would like to understand how exercise affects your blood results.
• You take medicines or supplements that can affect the liver and want a check.
• Your GP has suggested calculating a liver fibrosis score.

Understanding your result

Your report shows your AST with the laboratory reference range. A raised AST may come from the liver, for example with fatty liver, alcohol or hepatitis, but it can also rise after strenuous exercise, a muscle injury or, less commonly, heart or blood conditions. Your practitioner will compare it with ALT and other markers to work out the most likely source.

A single raised result is often repeated after a period without heavy exercise or alcohol. Anyone with chest pain should call 999 rather than book a blood test. An out-of-range level is a cue for a fuller discussion, never a diagnosis by itself.

Preparing for your test

Fasting is not required. To avoid a misleading result, please avoid heavy exercise for 48 hours and alcohol for 24 to 48 hours before your sample. Keep taking prescribed medicines and let us know what you take.

AST is part of our Liver Function Check, where it can be read with ALT and other markers, and it also appears in Omnia Essential Plus. Have a look at every blood test and price in Chiswick.

Questions

How much is an AST blood test in Chiswick?

An AST blood test costs £59 at Omnia. The price includes your sample at our W4 clinic, analysis at an accredited laboratory, a practitioner review and a GP feedback report on request.

Why test AST and ALT together?

AST is found in several tissues, while ALT is more specific to the liver. Looking at both, and the ratio between them, gives a clearer idea of where a raised result is coming from.

Can exercise affect AST?

Yes. Hard training, especially weights or long-distance running, can raise AST for a few days because it is released from muscle.

What is the FIB-4 score?

It is a calculation using your age, AST, ALT and platelet count to estimate the likelihood of liver scarring. It is used in NHS pathways to decide who needs further liver assessment.