More than 102 million adults in the United States have high cholesterol, according to the Centers for Disease Control and Prevention. In 2010, more than 35 million of these Americans had high enough blood serum cholesterol levels to put them at high risk for developing heart disease. Understanding the definition of blood serum cholesterol is the first step to controlling your risk for cardiovascular disease.
Serum
Blood carries cholesterol to the cells of the body. Blood is a complex substance, comprised largely of plasma, blood cells and platelets. When blood coagulates, the watery part of the blood, or serum, separates from the red and white blood cells. A medical laboratory can measure the amount of cholesterol in this serum.
Cholesterol
Cholesterol is a natural substance found in every cell membrane in your body. It is necessary in the production of bile acids, used in the digestive process. Cholesterol is vital in the manufacture of certain hormones, like estrogen or testosterone. You need cholesterol to metabolize vitamins A, D, E and K.
Lipids
Cholesterol is a molecule in a class called lipids. Lipids are fat-like substances, important in energy storage, cell membrane development and metabolism. Lipids are hydrophobic, which means they aren't soluble in water.
Transport
Your liver creates most of the cholesterol in your body, including the cholesterol in your blood serum. You gain the rest from the food you consume. The fat you eat is absorbed into the intestines, then goes into the liver. The liver converts fat into cholesterol and triglycerides. Cholesterol moves from the gut to the cells of the body through the bloodstream.
Excess
Your body uses most of the cholesterol it makes to create bile. Serum transports any remaining cholesterol to the cells of the body. Excess cholesterol builds up in the bloodstream, accumulating inside blood vessel walls. This accumulation injures arteries and prevents blood from flowing properly to all parts of the body, including vital organs like the heart, brain and kidneys. Doctors call this condition atherosclerosis. Chest pains or heart attack can result if the muscles of the heart do not receive the oxygen-rich blood they need to function. Improper blood flow may cause kidney disease or stroke.
Causes
Eating too much saturated fat and dietary cholesterol is the main reason for high cholesterol. You can reduce the amount of blood serum cholesterol by avoiding foods high in cholesterol. Animals produce cholesterol in their livers, so animal products like meat, eggs and dairy products contain cholesterol. Vegetables and fruit do not contain cholesterol.
