While cholesterol is essential to every cell in the body, too much contributes to plaques that builds up in the arteries and impedes normal blood flow. The best way to assess cholesterol and other blood lipids is a complete fasting lipoprotein profile, says the American Heart Association (AHA). A total blood (or serum) cholesterol level of less than 200 mg/dL is desirable. Even if your other levels are also in the desirable range, your blood pressure’s healthy, and you have no family history of heart disease, it’s still advisable to eat a heart-healthy diet, exercise regularly, and avoid tobacco smoke. 200-239 indicates borderline to risk, while 240 or more suggests high risk of coronary heart disease. Also pay attention to LDL (lousy) cholesterol levels, a better gauge of heart attack and stroke risk. Aim for under 100 mg/dL, and consult a healthcare provider if your levels are borderline high (130 to 159), high (160-189), or very high (190 or above).

Another dangerous form of fat to assess, triglycerides are best when under 150 mg/dL. Up to 199 is borderline high, 200-499 high, and 500 and over very high. While overweight, physical inactivity, alcohol or smoking, and a high-carb diet can push triglycerides up, so can underlying disease or genetic factors.

There’s one number you want high: HDL (healthy) cholesterol, which transports unnecessary cholesterol (including LDL) back to the liver, where it is broken down for removal from the body. Optimal levels are 60 mg/dL and above; less than 50 for women and 40 for men increase the risk for heart disease.