Cholesterol ratio: Is it important?

Cholesterol ratio has been useful as a predictor of heart disease risk. You can calculate your cholesterol ratio by dividing your high-density lipoprotein (HDL, or "good") cholesterol into your total cholesterol. For example, if your total cholesterol is 200 milligrams per deciliter (mg/dL) and your HDL cholesterol is 50 mg/dL, your cholesterol ratio is 4-to-1. The goal is to keep your cholesterol ratio below 5-to-1. A higher ratio indicates a higher risk of heart disease; a lower ratio indicates a lower risk.

However, cholesterol ratio is not useful when it comes to determining appropriate treatment to reduce the risk of heart disease. For treatment purposes, it is more important to know absolute numbers for all your cholesterol levels — including HDL, LDL (or "bad") and total cholesterol — rather than ratios. This is because HDL cholesterol and LDL cholesterol both affect your heart disease risk, and treatment may be directed at improving both. For example, if you have LDL cholesterol of 100 mg/dL or above, the main goal of treatment is to lower your LDL cholesterol. However, your doctor will also consider your HDL cholesterol when deciding on treatments and goals.