Cholesterol is a waxy substance manufactured by the body, necessary to make cell membranes, hormones and other compounds. Levels that are too high, however, can contribute to increased risk of coronary heart disease by depositing plaque along the artery walls which ultimately lead to blockage. The American Heart Association (AHA) recommends individuals get blood cholesterol levels tested beginning at the age of 20, and follow-up tests every five years thereafter as long as cardiac risk factors remain low.
Interpreting Total and Differential Cholesterol Levels
Step 1
Total serum cholesterol is generally the first test performed. This test shows the combined levels of the high density lipoproteins (HDL), the low density lipoproteins (LDL) and the very low density lipoproteins (VLDL). Desirable reading for total cholesterol is less than 200 milligrams per deciliter (mg/dl). A level between 200 and 239 mg/dl indicates a borderline high risk, according to the AHA, and warrants further evaluation of the HDL and LDL levels independently. A level above 240 mg/dl indicates high risk and typically suggests double the risk of coronary heart disease as people with levels below 200 mg/dl.
Step 2
The low density cholesterol (LDL) test provides more detailed information for the person who shows borderline high risk in their total cholesterol levels. LDL is the "bad" type, contributing plaque build up in the arteries. Desired LDL levels are below 130 mg/dl. LDL levels from 130-159 mg/dl are considered borderline high risk. High risk levels range from 160-180 mg/dl, and over 190 mg/dl puts a person into the very high risk range.
Step 3
HDL (high density lipoprotein) is known as "good cholesterol" because these packages carry harmful plaque away from the arteries, reducing plaque buildup. HDL level is better when it is higher. More of these packages are desirable in the bloodstream to lower the risk of coronary heart disease.
Levels tend to be higher in women. Less than 50 mg/dl is high risk in women and less than 40 mg/dl is high risk for men. Levels over 60 mg/dl have a protective effect over cardiovascular disease.
Step 4
The question arises, "how low is too low?" for total cholesterol. Levels down to 100 mg/dl are generally considered favorable, reflecting low coronary artery disease risk. Levels below 100 mg/dl, however, may indicate other conditions, according to the American Association of Clinical Chemistry. Low levels occur in liver disease, malnutrition and some forms of cancer. The cholesterol level is a reflection of a condition such as these, and not a cause. Raising cholesterol level will therefore not help correct one of these conditions.
Levels can also be temporarily reduced immediately after certain illnesses. Allow time to pass after a serious illness before testing cholesterol levels to produce reliable results.
Tips and Warnings
- A qualified physician is the best person to interpret cholesterol tests based on individual cases. Follow personal physician guidelines for how often tests should be repeated.
- Risk of coronary heart disease is not determined by cholesterol levels alone: Other factors that increase risk include smoking, obesity, and pre-exisiting heart conditions.
Things You'll Need
- Recent cholesterol test results
