Learning your numbers
If you’ve ever had your cholesterol measured, you probably know the routine: You skip breakfast, have a blood test, and get your cholesterol results a few days later. You’re probably familiar with your total cholesterol. That’s the number you want to keep below 200. You calculate total cholesterol by adding up the following numbers:
- high-density lipoprotein (HDL), or good cholesterol
- low-density lipoprotein (LDL), or bad cholesterol
- 20 percent of your triglycerides, a type of fat carried in your blood
But what about your cholesterol ratio? Learn what this health statistic tells you.
Your cholesterol ratio is calculated by dividing your total cholesterol by your HDL number. For instance, if your total cholesterol is 180 and your HDL is 82, your cholesterol ratio is 2.2. According to the American Heart Association (AHA), you should aim to keep your ratio below 5, with the ideal cholesterol ratio being 3.5. Read about the effects of high cholesterol here.
According to the Framingham Heart Study, a cholesterol ratio of 5 indicates average risk of heart disease for men. Men have double the risk for heart disease if their ratio reaches 9.6, and they have roughly half the average risk for heart disease with a cholesterol ratio of 3.4.
Because women often have higher levels of good cholesterol, their cholesterol ratio risk categories differ. According to the same study, a 4.4 ratio indicates average risk for heart disease in women. Heart disease risk for women doubles if their ratio is 7, while a ratio of 3.3 signifies roughly half the average risk.
Two people with the same total cholesterol number can have different cholesterol ratios. The ratios indicate different levels of heart disease risk. Harvard Medical School cites the following example: If your total cholesterol is 200 and your HDL is 60, your cholesterol ratio would be 3.3. That’s near the AHA’s ideal level. However, if your HDL is 35 — below the recommended level of 40 for men and 50 for women — your cholesterol ratio would be 5.7. This ratio places you in a higher risk category.
Some people may find it easier to remember their cholesterol ratio — one number — than their HDL, LDL, and total numbers. This is fine if you’re in a low-risk category, but if your bad cholesterol has climbed, it’s best to pay attention to all of your numbers. Knowing your total cholesterol and the risk indicated by your cholesterol ratio helps you set the appropriate goals to keep your numbers in a healthy range.
The AHA believes that absolute numbers for total blood cholesterol and HDL cholesterol are more effective than a ratio in determining cholesterol-lowering treatment. But both are useful in looking at your overall risk. If your total cholesterol level is high, your doctor will also look at the ratio of your total cholesterol to HDL. If that number is below 5 for a man or 4.4. for a woman, placing you at average risk, your doctor may consider this in the overall evaluation of your risk.
Your cholesterol ratio clarifies the picture of your risk of heart disease. But the ratio alone isn’t enough to assess what treatment will be best if your risk is high. Your doctor will take your total cholesterol into account when determining the correct mix of diet, exercise, and medication to bring your numbers into the desirable range.