There's a lot of news about cholesterol these days, and with good reason. High cholesterol contributes to heart disease, which kills more Americans than all cancers combined.
What is cholesterol?
Cholesterol is a waxy, fatlike substance that your body – mainly the liver – produces. Cholesterol is used to make some hormones, vitamin D, and bile acids, which help to digest fat. Cholesterol also is used to build healthy cell membranes (walls) in the brain, nerves, muscles, skin, liver, intestines, and heart. It only takes a small amount of cholesterol to meet all these needs. Your body makes enough; you don't have to get cholesterol in your diet.
Why is a high cholesterol level unhealthy?
Cholesterol causes a problem only when you have too much of it in your blood. Excess cholesterol is deposited in the lining of the arteries, including the arteries that feed your heart muscle. This narrows the area inside the artery, through which blood flows. High blood cholesterol itself does not cause symptoms, so many people are unaware that their cholesterol level is too high.
You should have your cholesterol checked at least every five years if your cholesterol is normal, starting at age 20. The most accurate test is a lipoprotein profile, a blood test given after fasting for 10 to 12 hours. The test will give you these details:
Your total cholesterol
Your LDL ("bad") cholesterol; this cholesterol is what's deposited in your arteries
Your HDL ("good") cholesterol; this cholesterol helps keeps deposits from building up in your arteries
Your triglycerides; these are another form of fat in your blood
Even without a lipoprotein profile, you can get a rough idea of your cholesterol health if you know your total cholesterol and HDL cholesterol. These levels can be determined through a non-fasting cholesterol test often given at shopping malls or health fairs. If your total cholesterol is 200 mg/dL or more, or if your HDL cholesterol is less than 40 mg/dL for men and less than 50 mg/dL for women, you should ask your doctor about getting a complete lipoprotein profile.
For adults, a total cholesterol level of 190 mg/dL to 224 mg/dL is considered borderline high. Anything above 225 mg/dL is high.
HDL (high-density lipoprotein) cholesterol
An HDL level of less than 40 mg/dL for men and 50 mg/dL for women is low; 60 mg/dL and above is considered optimal. The higher your HDL cholesterol, the better, because it helps protect against heart disease.
LDL (low-density lipoprotein) cholesterol
The National Heart, Lung, and Blood Institute says that 100 mg/dL is an optimal LDL level. An LDL level of 120 to 159 mg/dL is considered borderline high; 160 mg/dL and above is high to very high. For people with known heart disease and diabetes, the cholesterol level targets are more stringent; ask your doctor what they are. Having a high level of LDL cholesterol can cause fatty plaque to form along the insides of your artery walls. This makes the arteries narrower and stiffer. Narrower arteries mean less room for blood to flow through – like a partially clogged pipe. This process, called atherosclerosis, develops over a long time. It is especially dangerous if it narrows the vessels to the heart and brain, creating a major risk for heart attack and stroke. Build-up of cholesterol in the arteries of the legs can cause leg and foot pain and trouble walking.