Total cholesterol is a measurement of both good and bad cholesterol. Cholesterol/HDL ratio is another measurement used to determine cardiovascular disease (CVD) risk and is obtained by dividing the total cholesterol by HDL-cholesterol to assess the levels of good and bad cholesterol in relation to each other. If you have a high level of total cholesterol, your risk of CVD is less if your total-to-HDL ratio is low.
The Total cholesterol/HDL ratio has been demonstrated to have a better predictive capacity for for CVD than the total cholesterol and HDL values used alone and is particularly useful if the individual lipid values are within reference ranges. The smaller the number the better. The HDL ratio is useful to estimate heart disease risk but not as important in guiding treatment.
The HDL ratio should be below four and the higher the ratio the higher your risk of heart disease. Individuals with a high total/HDL cholesterol ratio have a greater cardiovascular risk due to an imbalance between ‘good’ and ‘bad’ cholesterol. This can be caused by an increase in the non-HDL components of the total cholesterol or a decrease in the HDL fraction. Doctors may set individual cholesterol targets based on overall risk factors including obesity, family history of cardiovascular events and blood pressure.