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The platelet/lymphocyte ratio is the ratio between the number of platelets and the number of lymphocytes in your blood. A shift in that ratio can point to acute inflammation or to a tendency of the blood to clot.[1]
On this page you can read what the platelet/lymphocyte ratio is, what the guidelines say about a value that is too low or too high, what affects your value and which values are best to read alongside it.
Also known as: PLR, platelet-to-lymphocyte ratio, platelet/lymphocyte ratio. At the lab: n/a.
The platelet/lymphocyte ratio is not a single blood cell. It is a ratio between two counts from your blood count: the platelets and the lymphocytes.[1]
Researchers use this ratio as an inflammation marker. It shows how both counts shift with acute inflammation and with a tendency of the blood to clot.[1]
The ratio has been widely studied in serious conditions in which the immune system is suppressed and the blood clots more quickly.[1]
Several large observational studies show that shifts in this ratio help estimate how severe inflammation throughout the body is. This concerns inflammatory diseases of the joints, muscles and immune system.[1]
In those inflammatory diseases, the shifts also help estimate whether additional conditions may develop.[1]
A high value together with a high platelet count can help a doctor recognise some forms of inflammation of the blood vessels, especially inflammation of the large arteries.[1]
| Level | Can point to | Who it is for |
|---|---|---|
| Shifted[1] | Acute inflammation or a tendency of the blood to clot | Described as a general inflammation marker |
| Shifted[1] | How severe inflammation throughout the body is and the risk of additional conditions | People with an inflammatory disease of the joints, muscles or immune system |
| High, together with a high platelet count[1] | Some forms of inflammation of the blood vessels, especially of the large arteries | People in whom a doctor is investigating this kind of inflammation |
| Falling over time[1] | A response to care that dampens inflammation | People with an inflammatory disease of the joints or immune system, in a few long-term studies |
Source: Gasparyan and colleagues, a review article on the platelet/lymphocyte ratio as an inflammation marker in inflammatory diseases of the joints, muscles and immune system. The source gives no fixed cut-off values.[1]
A high value can point to acute inflammation or to a tendency of the blood to clot. Together with a high platelet count, it can help in recognising some forms of inflammation of the blood vessels. The source advises always reading the value together with other blood values.[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.
With acute inflammation and with a tendency of the blood to clot, your platelet and lymphocyte counts shift. As a result, the ratio changes too.[1]
A few long-term studies in inflammatory diseases of the joints and immune system saw the ratio fall during care that dampens inflammation. In this way, the value shows how it develops during care.[1]
Errors before the blood is measured in the lab and differences in how labs measure can affect the result. According to the source, these are the biggest limitations of research into this value.[1]
The platelet/lymphocyte ratio is included in all five packages, from BioProfile 31 to BioProfile 150.[2]
The BioProfile editorial team wrote this page on 23 October 2026 from the sources below, which we read on 23 October 2026. Every number on this page appears in one of those sources, with that source's number beside it. An expert has yet to review this page; after that review, the expert's name and the date of the review will appear at the top. This page offers explanation, not a diagnosis. Discuss a value outside the normal range with your GP.
