Knowing your total cholesterol level isn't enough—your LDL and HDL levels may be even more enlightening if you're concerned about lowering heart-disease risk. Many doctors recommend that total blood cholesterol be less than 200 mg per deciliter (mg/dl) of blood, with LDL less than 100 mg per deciliter and HDL more than 40 to 60 mg per deciliter. But debate continues: John McDougall, MD, co-author of The McDougall Program for a Healthy Heart (Plume, 1998), recommends a total cholesterol level of less than 150 and an LDL level of less than 80. Genetics, diet, and other lifestyle factors all play a role when you assess what levels are healthy for you. At your next checkup, talk to your doctor about getting a total cholesterol test (about $10). Better yet, request a full screening that includes HDL and LDL levels (around $40). Get checked at least once a year—or more often if you're trying to lower your cholesterol levels.

—L.T.