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The De Ritis ratio is the balance between two enzymes in your blood: AST divided by ALT. If ALT is higher than AST, this can point to an acute inflammation of the liver caused by a virus. If AST is higher than ALT, this is often seen in inflammation of the liver caused by alcohol.[1]
On this page, you can read what the De Ritis ratio is, what the guidelines say about a value that is too low or too high, what affects your value and which other values are best looked at alongside it.
Also known as: AST/ALT ratio, ASAT/ALAT ratio. At the lab: n/a.
AST and ALT are two enzymes measured in your blood. The De Ritis ratio is the AST value divided by the ALT value. So it is not a separate measurement, but a calculation from two measurements.[1]
De Ritis described this ratio almost 50 years before the review by Botros and Sikaris was published. At first, the ratio was seen mainly as a sign of acute inflammation of the liver caused by a virus. Later, it also proved useful in inflammation of the liver caused by alcohol.[1]
The ratio shows how a liver condition develops over time. This is because AST stays in your blood for a shorter time than ALT. In this way, the ratio also says something about how severe the course is.[1]
In long-term inflammation of the liver caused by a virus, in long-term heavy drinking and in fatty liver not caused by alcohol, a raised ratio can predict long-term complications. These include scarring of the liver.[1]
Botros and Sikaris believe that every lab that reports an abnormal ALT should also report AST and calculate the ratio. This is because the ratio gives useful information about the cause and how things are likely to develop.[1]
| Ratio | Can point to | Who it is for |
|---|---|---|
| ALT higher than AST[1] | acute viral inflammation of the liver, where this is the usual pattern | people with acute viral inflammation of the liver |
| AST higher than ALT[1] | alcohol-related inflammation of the liver, where this is the usual pattern | people with alcohol-related inflammation of the liver |
| AST higher than ALT[1] | a very severe course | people with acute viral inflammation of the liver |
| ALT higher than AST[1] | a point when several days have already passed since drinking alcohol | people with alcohol-related inflammation of the liver |
| Raised ratio[1] | a higher risk of long-term complications, such as scarring of the liver | people with long-term viral inflammation of the liver, long-term heavy alcohol use or a fatty liver not caused by alcohol |
Source: Botros and Sikaris, review article on the De Ritis ratio. The article gives no fixed cut-off values, only which of the two enzymes is higher.[1]
A high ratio means AST is higher than ALT. This is often seen in inflammation of the liver caused by alcohol. In acute inflammation caused by a virus, it can point to a severe course. In long-term liver conditions, a raised ratio can point to a higher chance of scarring.[1]
A low ratio means ALT is higher than AST. This is the usual picture in acute inflammation of the liver caused by a virus. It can also point to inflammation caused by alcohol where the drinking was a few days ago.[1]
BioProfile is working on its own zones for each value, from risk to optimal. A doctor reviews those zones before they appear in your result.
After about 18 hours, half of the AST has left your blood. For ALT, that takes about 36 hours. The longer ago a liver condition started, the more this shifts the ratio.[1]
In inflammation of the liver caused by alcohol, AST is usually higher than ALT. If a few days have passed since drinking, ALT can actually be higher.[1]
Labs measure AST and ALT with or without added pyridoxal phosphate, a form of a vitamin. If you are low in this vitamin, that difference can affect the result. The effect on the ratio is usually small. A deficiency may be more common in older people and in people who drink a lot of alcohol.[1]
The De Ritis ratio is included in BioProfile 77, 87, 121 and 150.[2]
The BioProfile editorial team wrote this page on 27 October 2026 from the sources below, which we read on 27 October 2026. Every number on this page comes from one of those sources, with that source's number next to it. An expert will still review this page; after that review, the expert's name and the date of the review will appear at the top. This page explains and does not diagnose. Discuss an abnormal value with your GP.
