Understanding cholesterol and blood lipids helps you reduce your risk for developing heart disease. More than 102 million adults in the United States have high cholesterol, according to the Centers for Disease Control and Prevention. More than 35 million Americans have levels high enough to put them at risk for cardiovascular disease.
Definition
Lipids are fatty, waxy or oily substances that do not dissolve in water. Lipid molecules are made of hydrogen, carbon and oxygen, according to the National Institute of General Medical Sciences. Lipids include fat, cholesterol, triglycerides, steroids, hormones and other waxy chemicals. Cholesterol is a type of lipid.
Cholesterol
Cholesterol is present in every cell membrane in the body and is essential to body function. Most cholesterol in the body is used to make the digestive juice, bile. Cholesterol is an important component in cell membrane development and is vital for the production of certain hormones, like estrogen and testosterone. It is necessary in making digestive juices and skin oils. Cholesterol is also necessary for the metabolism of some vitamins, including vitamins A, D, E and K.
Source
Your liver produces most of the cholesterol in your body. You consume the rest with the foods you eat. You do not need to eat any cholesterol for your body to function properly -- your body would make up for it by producing more cholesterol. Cholesterol moves from the gut to the cells of the body via the bloodstream.
Lipoproteins
Cholesterol is a waxlike substance not soluble in the watery plasma of blood. The body overcomes this by packaging cholesterol onto lipoproteins. Lipoproteins have a special protein-based coating that allows them to move through the bloodstream. There are several types of lipoproteins, categorized by density.
Transport
Low-density lipoprotein, or LDL, moves cholesterol from the gut to the waiting cells of the body, including the cells that line blood vessel walls. LDL is unhealthy because it releases excess cholesterol into the bloodstream. High-density lipoprotein, or HDL, scrapes excess cholesterol from arterial walls and transports it to the liver where it is processed and eliminated from the body.
Risk
Excess cholesterol builds up in the blood and accumulates inside blood vessel walls. This accumulation injures arteries and prevents blood from flowing efficiently to all parts of the body including vital organs. Doctors call this condition atherosclerosis, a type of heart disease. Blockage to the heart may cause chest pains or even heart attack.
Measurement
A blood test measures the amount of cholesterol in the bloodstream. You can get a cholesterol screen from your doctor, at a health fair or even with a home testing kit. High levels of blood cholesterol are associated with heart disease. A healthy cholesterol level measures 200 mg/dL or less, according to LabTestsOnline.org. Cholesterol levels over 239 are high. A healthy LDL measures 100 mg/dL or less. LDL levels above 160 mg/dL are linked to heart disease. High levels of HDL are healthy, offering more protection against cardiovascular disease. Your HDL should be 60 mg/dL or higher.
