Cholesterol is a soft, waxy, natural substance found in your bloodstream and every cell in the body. Its purpose is to help body cells work together as a unit instead of being an inactive mass of individual, disconnected cells. Maintaining proper levels of cholesterol is essential for good health and to avoid ailments such as clogged arteries, which can lead to heart disease, heart attack or stroke.
Blood tests, called lipid profiles, are administered to obtain one of three cholesterol levels: A measurement of total cholesterol, one for LDL (low density lipoprotein) cholesterol and another for HDL (high density lipoprotein) cholesterol. It is recommended that you refrain from eating or drinking (other than water) 9 to 12 hours prior to the test so that accurate readings will be obtained. In select cases, a measurement is taken of very low density lipoprotein (VLDL) when an individual suffers from the condition causing the presence of small, dense LDL. In the United States, blood cholesterol levels are measured in milligrams per decilitre of blood (mg/dl), but in Canada and Europe, the standard of measure is millimoles per litre of blood, (mmol/L). (See References below for more details.)
Low density lipoprotein is known as "bad" cholesterol since it clogs the arteries, but HDL is termed "good" because it has been linked to prevention of blocked arteries. According to the National Cholesterol Education Program, a fasting, cholesterol blood test should be taken every five years by anyone over the age of 20.
If you are at high risk for heart disease your LDL level should be lower than normal and if you are extremely high risk, your recommended rate is reduced even further. You fall in the extreme risk category if you have a history of heart attack, diabetes or vascular disease. Additionally, the presence of tow or more of these factors can put you at high risk as well: smoking, high blood pressure, low HDL and a family history of heart disease.
A total cholesterol measurement includes the LDL, HDL and VLDL with the recommended level being below 200 mg (5.2 mmol). Levels greater than 240 mg (6.2 mmol) are considered high, while 200-239 mg (5.2 -- 6.2 mmol) is just below high. (See References)
Normal LDL levels are said to be under 70 mg (1.8 mmol) for extremely high risk individuals and below 100 mg (2.6 mmol) for those of high risk. A rate of 100-129 mg (2.6-3.3 mmol) is near normal, 130-159 mg (3.4-4.1 mmol) is borderline high, 160-189 mg (4.1-4.9 mmol) is high and over 190 mg (4.9 mmol) is very high.
The recommended HDL level is 60 mg or more (1.5 mmol), followed by 50-59 mg (1.3-1.5 mmol). The poorest levels are below 40 mg (1 mmol) for men and 50 mg (1.3 mmol) for women.
Triglycerides also are measured with cholesterol blood tests. They are fats found in the blood that--like cholesterol--are unable to dissolve in the bloodstream so they end up being carried through the body with the help of lipoproteins. Levels below 150 mg (1.7 mmol) are ideal, followed by 150-199 mg (1.7-2.2 mmol), which is on the brink of being high, 200-499 mg (2.3-5.6 mmol) is high and over 500 mg (5.6 mmol) is said to be very high.