Cholesterol is a waxy steroid needed for life. It is part of every cell membrane and is needed for vitamin D synthesis, hormone production and fat digestion. Your liver makes cholesterol and you get it through foods from animal sources. Cholesterol is transported throughout your body by lipoproteins, which are made of fat and protein. Low density lipoproteins transport cholesterol to your cells; high density lipoprotein carries excess cholesterol back to your liver to be broken down. When you have too much cholesterol in your blood, it can build up on the walls of your arteries and lead to atherosclerosis.
What is Measured
A simple blood test measures total cholesterol, as well as your levels of low density lipoprotein -- or LDL -- and high density lipoprotein -- or HDL. Your triglyceride level is usually measured at the same time, but triglycerides are not cholesterol. A high level of LDL is considered a risk factor for heart disease, but a high level of HDL lowers your risk. LDL is commonly called the "bad" cholesterol and HDL is commonly called the "good" cholesterol.
The Test
A man should have cholesterol tested for the first time between 20 to 35 years of age; a woman should be tested between 20 to 45 years. After the first screening, you should be tested every five years. Genetic disorders can require testing to begin as early as infancy.
For the best results, you should be fasting for nine to 12 hours before the test. It's okay to drink water, but no other beverages or food should be consumed. Your doctor may advise you to skip doses of drugs that can affect cholesterol readings. For the test, the medical technician draws blood from a vein, usually at the inside of the elbow. If the test is being done on an infant or very young child, a lancet is used to puncture the skin and blood is collected from the puncture site.
Test Results
A desirable total cholesterol reading should be 200 mg/dL or less. Borderline high is between 200 and 239 mg/dL, while a high reading is over 240.
A desirable LDL reading is under 100 mg/dL, while 100 to 129 is considered near optimal. Borderline high is 130 to 159 mg/dL, high is 160 to 189 and very high is over 190.
Unlike total cholesterol and LDL, a high HDL reading is desirable. A desirable HDL level is 60 mg/dL or above, while an undesirable reading is less than 40 mg/dL for men and less than 50 mg/dL for women.
How to Improve Cholesterol Levels
High LDL and total cholesterol are risk factors for heart disease, as is a low HDL level. To improve your cholesterol levels, reduce your intake of saturated fat, increase your intake of dietary fiber and reduce portion sizes to lose weight. Consistent exercise will also help to improve your cholesterol levels, particularly your HDL, as well as aid in weight loss and maintenance.
