Why can I not see my LDL?

Created by Louis Matthews-Ratner, Modified on Mon, 28 Apr at 5:45 PM by Jo Ratner

There are two common methods for reporting 'bad' cholesterol, referred to as 'non-HDL' and 'LDL'.

Non-HDL

Non-HDL is a simple calculation of your total cholesterol less your HDL cholesterol. It represents all the 'bad' cholesterol added together, which mainly includes LDL cholesterol. As long as the test chip result is valid, we will always be able to calculate non-HDL.

LDL

We use the Friedewald calculation for LDL. It represents only the LDL part of the 'bad' cholesterol in your blood. LDL is your total cholesterol less your HDL cholesterol, less 20% of your triglycerides.

If any of the measured markers (i.e. total cholesterol, HDL or triglyceride) are below or above the levels we can measure, it is not possible to calculate LDL. When this happens, we show, "Not calculated - Input value outside of limit of quantification".

Please note, this does not mean the test has failed, or that there is anything unusual about the result. It is often not possible to calculate LDL, which is why most healthcare professionals refer to non-HDL as a reliable measure of 'bad' cholesterol.