The presence or absence of certain substances in your blood may provide clues that help your doctor make an accurate diagnosis. For instance, a small sample of your blood can reveal blood levels of medicine you took, show the presence or absence of infection, or indicate whether you've had or are at increased risk of a heart attack or stroke . That is why one of the first things your doctor may do during a routine examination or when a heart condition is suspected is to take a sample of your blood. Cholesterol is a major contributor to risk of cardiovascular disease. The higher the total cholesterol level, the greater your risk of cardiovascular disease.
Triglycerides are also lipids that are associated with increased risk of cardiovascular disease.
The higher the triglyceride level, the greater the risk of cardiovascular disease. There is some evidence that triglyceride levels may play a greater role in cardiovascular disease in women than in men. Your blood's lipid level is not a constant and can vary by what you eat. To get an accurate lipid level, your blood should be drawn after you have fasted for about 12 to 14 hours. If you have a family history of atherosclerosis, it is a good idea to begin having your blood lipid levels tested at an early age, such as in your teenage years.