LDL stands for low-density lipoprotein, which is one of the five major groups of lipoprotein that transport all fat molecules around the body in extracellular water. LDL cholesterol is often called "bad" cholesterol because it contributes to plaque buildup (atherosclerosis) in your arteries, which can lead to heart disease. LDL particles are approximately 22 nm to 27.5 nm in diameter and have a mass of about 3 million daltons. Since LDL particles contain a variable and changing number of fatty acid molecules, there is a distribution of LDL particle mass and size.

LDL cholesterol levels can be measured through a simple blood test called a lipid panel. The test measures the amount of LDL cholesterol in your blood, and results are typically measured in milligrams per deciliter (mg/dL) . Lowering LDL-C levels can help prevent heart disease, and the optimal level of LDL depends on all your risk factors. Generally, a LDL cholesterol level of 100 mg/dL may be a good goal, and a level below 70 mg/dL is considered best for people who have diabetes or heart disease risk factors.

LDL cholesterol can be lowered through lifestyle modifications, such as a well-balanced diet that derives a low proportion of energy from saturated fatty acids and a high proportion from polyunsaturated fatty acids. Pharmacological interventions can also be considered for individuals with LDL-C above 115 mg/dL.

In summary, LDL is a type of lipoprotein that carries fats through the bloodstream, and high levels of LDL cholesterol can contribute to plaque buildup in the arteries, leading to heart disease. LDL cholesterol levels can be measured through a blood test, and can be lowered through lifestyle modifications and pharmacological interventions.