Although many people think of cholesterol as a bad or dangerous thing, some cholesterol is necessary for good health. Your body needs cholesterol to build cell membranes and produce certain hormones. Not all cholesterol is unhealthy, which makes it important to understand the differences between "types" of cholesterol. Consult your doctor for more information about your cholesterol levels and overall health.
Types of Cholesterol
Cholesterol travels through your bloodstream in different types of "packages," called lipoproteins. There are two major types:: high-density lipoprotein, or HDL, and low-density lipoprotein, or LDL. HDL molecules bind to cholesterol in the blood and bring it to the liver, where it is excreted or reused by the body. HDL cholesterol is often called "good" cholesterol because it removes cholesterol deposits from your arteries. LDL cholesterol, on the other hand, is known as "bad" cholesterol. LDL molecules transport cholesterol to the arteries and promote plaque formation. High LDL cholesterol levels increase your risk of cardiovascular disease.
Cholesterol Testing
Doctors measure your cholesterol levels by drawing and analyzing your blood. A typical lipid profile gives you information about your levels of total cholesterol, HDL cholesterol, LDL cholesterol and triglycerides. You should not eat or drink for 9 to 12 hours before your cholesterol test to ensure accurate results. Total cholesterol levels under 200 mg/dL are considered healthy. HDL levels should be above 60 mg/dL, while LDL levels should remain below 100 mg/dL. People at high risk of cardiovascular disease should keep their LDL cholesterol levels below 70 mg/dL. Your doctor can provide more information about appropriate LDL and HDL cholesterol levels for you.
Ratio
Some medical professionals use the ratio of LDL to HDL cholesterol as a measure of cardiovascular risk. To find this cholesterol ratio, divide your LDL level by your HDL cholesterol level. For example, someone with a LDL cholesterol level of 100 mg/dL and an HDL cholesterol level of 30 mg/dL has a LDL to HDL ratio of 100:30, or 3.3. Men should keep their LDL to HDL ratios below 3.6, while women should aim for a ratio below 3.2. Higher LDL to HDL ratios put you at greater risk for heart disease.
Considerations
Although knowing your ratio of HDL to LDL cholesterol may be useful in determining cardiovascular risk, understanding the absolute values of HDL and LDL cholesterol may be more helpful. MayoClinic.com states that knowing your HDL and LDL levels is more important than cholesterol ratios when evaluating treatment options. For example, a person with an HDL level of 60 mg/dL and an LDL level of 150 mg/dL has an HDL to LDL ratio of .4, which is considered healthy. However, her absolute LDL level is in the borderline high range, which raises her overall cardiovascular risk.
References
- Net Nutritionist; Cholesterol Ratio Calculator; Gay Riley
- MayoClinic.com; Cholesterol Ratio: Is It Important?; Thomas Behrenbeck; Jan. 2010
- ExRx: Blood Cholesterol (HDL and LDL)
- Family Doctor; Cholesterol: What Your Level Means; Nov. 2010
- MayoClinic.com; High Cholesterol: Tests and Diagnosis; June 2010
