Blood

"Blood is a constantly circulating fluid providing the body with nutrition, oxygen, and waste removal. Blood is mostly liquid, with numerous cells and proteins suspended in it, making blood ""thicker"" than pure water. The average person has about 5 liters (more than a gallon) of blood.
A liquid called plasma makes up about half of the content of blood. Plasma contains proteins that help blood to clot, transport substances through the blood, and perform other functions. Blood plasma also contains glucose and other dissolved nutrients.
About half of blood volume is composed of blood cells:
• Red blood cells, which carry oxygen to the tissues.
• White blood cells, which fight infections.
• Platelets, smaller cells that help blood to clot.
Blood is conducted through blood vessels (arteries and veins). Blood is prevented from clotting in the blood vessels by their smoothness, and the finely tuned balance of clotting factors."

Hypercholesterolemia

Hypercholesterolemia, or high cholesterol, occurs when there is too much cholesterol in the body. Cholesterol is a soft, waxy, fat-like substance that is a natural component of all the cells of the body. Your body makes all the cholesterol it needs. Any added cholesterol, which comes through the foods you eat, can cause harm.
High cholesterol raises your risk for heart disease, heart attack, and stroke. When there is too much cholesterol circulating in the blood, it can create sticky deposits (called plaque) along the artery walls. Plaque can eventually narrow or block the flow of blood to the brain, heart, and other organs. And blood cells that get caught on the plaque form clots, which can break loose and completely block blood flow through an artery, causing heart attack or stroke. There usually aren't any symptoms of high cholesterol, especially in early stages. The only way to tell if your cholesterol is high is through a blood test.
Causes:
In some cases, high cholesterol levels may be inherited -- your liver may make too much cholesterol, or your body may not remove LDL from your blood as efficiently as normal. High cholesterol or triglycerides can also be associated with other diseases, such as diabetes. But most often high cholesterol is caused by eating foods high in saturated fat and not getting enough exercise. High cholesterol is more common in people who are overweight or obese, a condition that affects almost half of U.S. adults.