Cholesterol and triglyceride tests are blood tests which measure the quantity of lipids (cholesterol and triglycerides) in the blood. Cholesterol is bound to a protein as it travels in the blood. This cholesterol-protein package is known as a lipoprotein. Lipoprotein analysis makes it possible to see levels of total cholesterol, LDL cholesterol, HDL cholesterol and triglycerides in the blood. The abbreviation LDL stands for "low-density lipoprotein". LDL cholesterol transports fat and a small amount of protein from the liver to other parts of the body.
A normal level of LDL cholesterol in the blood is healthy, as cholesterol is then transported out to parts of the body that need it. However, LDL cholesterol is sometimes known as "bad cholesterol" as an elevated level of it in the blood may increase the risk of developing cardiovascular disease. For adults, it is considered appropriate to check cholesterol levels every 4 to 6 years, particularly if you are at risk of cardiovascular disease.
High levels are seen in primary and secondary hyperlipoproteinaemia. The secondary levels are seen in cases of hypothyroidism, nephrotic syndrome, cholestatic liver disease and diabetes mellitus, for instance.
Low levels are seen in patients with hyperthyroidism, malabsorption and congenital beta lipoprotein deficiency (acanthocytosis).