The form of fat in the bloodstream is lipids. When you have blood lipid profile tested, your blood is drawn and the levels of lipoproteins and cholesterol are measured.
Fat is not water soluble, meaning that it does not dissolve in water. Blood is mainly water, and it is the major transportation highway in the body. For fat to travel effectively in the blood, which is necessary, it must be wrapped up and packaged for the trip. Lipoproteins enter the scene here. A lipoprotein is a combination of a fat and protein, and its main function is to transport fat in the blood. Fat adheres to other fat molecules if they come in contact with each other, so a lipoprotein is essentially a protein envelop for the fat to keep it separate from other fats. There are two main types of lipoproteins.