Cholesterol is a fatty, waxy substance that’s found in all cells of the body. Cholesterol is needed to make hormones, vitamin D, and substances that aid in digestion. Your body produces all the cholesterol it needs, but since cholesterol is also found in your diet, your levels may be too high, increasing your risk of coronary heart disease, heart attack and stroke.
There are two types of cholesterol: low-density lipoprotein (LDL) and high-density lipoprotein (HDL). LDL is called “bad cholesterol” because it forms plaque in the artery walls, making it harder for blood to circulate properly. Plaque buildup can cause blood clots or blockage, which can lead to a stroke or heart attack. HDL is referred to as “good cholesterol” because it helps remove LDL cholesterol from the arteries and carries it back to the liver, where it’s broken down.
Cholesterol levels are measured through a blood test taken after fasting for 12 hours to eliminate the effects of any recently eaten food. Your test results will show your levels of HDL and LDL in milligrams per deciliter of blood (mg/dL) and will also factor in your level of triglycerides, a common type of fat. Total blood (or serum) cholesterol is the amount of HDL plus LDL plus 20 percent of your triglyceride level.
What the numbers mean:
  • For HDL, higher is better. 60 mg/dL or higher is good, 40 to 59 is acceptable, and less than 40 is low
  • For LDL, lower is better: less than 100 mg/dL is optimal, 100 – 129 is acceptable, 130 – 159 is borderline high, 160 – 189 is high and 190 or more is very high.
  • For total cholesterol, 200 mg/dL is normal, 201 – 239 is acceptable and more than 240 is high
If your cholesterol levels aren’t optimal, you may be able to bring them into a healthy range with a diet that’s high in fiber and low in saturated fat, along with regular aerobic exercise. Your doctor may also prescribe cholesterol-controlling medication. The National Cholesterol Education Program recommends that adults have their cholesterol checked every five years. Your doctor’s recommendations may vary depending on your age, risk factors and overall health status.