1. Cholesterol Is in the Blood
Serum cholesterol refers to the amount of cholesterol in your blood, or serum. Cholesterol is a fatty substance that your body naturally makes. Cholesterol helps your body produce certain necessary hormones, and it's a building block for your cells. Aside from the cholesterol your body naturally makes, your body obtains cholesterol from the foods you eat. A total serum cholesterol blood test measures high-density lipoprotein (HDL), low-density lipoprotein (LDL) and the total cholesterol reading. A serum cholesterol blood test also includes triglycerides. Your body uses triglycerides as stored fat from excess calories.
2. Look for Healthy Readings
The total serum cholesterol, which is a combination of the HDL and LDL should be below 240, with less than 200 the optimum reading. A blood test that shows total cholesterol between 200 and 239 is considered borderline high. Any total cholesterol reading that's above 240 is considered high. HDL readings should be 60 or above for optimum good health. HDL readings that are below 40 are considered high-risk readings. LDL readings should be below 130 and some heart patients are told to keep the LDL as low as 70. Readings of LDL that are 160 or above are considered high.
3. LDL Is a Low Life, But HDL Is My Hero
An easy way to remember the good cholesterol from the bad is "HDL is my hero, but LDL is a low life." LDL circulates in your blood stream as fatty deposits, which later become plaque. The plaque causes a narrowing in your blood vessels and causes hardening of the arteries, or atherosclerosis. Because the blood flow is restricted, people with a high LDL reading are at a greater risk for heart attack and stroke. HDL is the good cholesterol, and just like a hero it removes the LDL from the blood stream. The higher your HDL cholesterol is, the more bad cholesterol is removed.
4. Related Testing May Be Required
Many doctors order additional blood tests on the same blood sample. Lipoprotein "a" is a component of the LDL that is more affected by genes than by lifestyle or food. C-reactive protein may be tested to check your immune response. Immune responses cause inflammation and increase the risk of stroke or cardiac events. Homocysteine levels may also be checked to determine if you're at risk for peripheral artery disease. Nuclear magnetic resonance testing is sometimes performed to do a complete count of and measure the size of the LDL and HDL.
5. Factors That Affect Serum Cholesterol Tests
Serum cholesterol blood tests are done on fasting blood, so it's important not to eat or drink anything but water for at least 8 hours before your blood test. Some over-the-counter medications can increase cholesterol readings. Hormone medications and birth control pills can also alter the serum cholesterol readings. Pregnancy, illness or severe stress can increase cholesterol levels. Talk to your doctor, before you have a cholesterol test, about medications you can take.
