Despite the fact that high cholesterol puts a person at risk for heart disease, cholesterol in and of itself has an undeservedly bad rep. A fatty alcohol that resides in your bloodstream and your cell membranes, cholesterol is by no means the bad guy. Without cholesterol, you'd be in a sorry state--simply put, it's essential to your body. Directly or indirectly, cholesterol affects the digestive, endocrine (immune), and circulatory systems of the body. Cholesterol is both eaten as food and manufactured by the body.  Learn the essential role of cholesterol and what can go wrong in the case of high cholesterol.

Last Updated: October 17, 2009

Here is what cholesterol does in your body:

Cholesterol gets transported throughout your body by lipoproteins. Lipoproteins consist of both protein and cholesterol. One type of lipoprotein is HDL, the "good cholesterol," which stands for high-density lipoprotein. It's the job of HDL to carry cholesterol to the liver so that it can get removed from the body. When you have high levels of HDL cholesterol, the implication is that any cholesterol your body doesn't need is taking the fast exit out.

LDL is low-density lipoprotein. LDL transports cholesterol into your bloodstream. Since your body needs cholesterol for many systemic processes, including the production of sex hormones and maintaining cellular structure, LDL, too, is essential for your health.

The problem comes when the ratio of LDL to HDL is too high--that is, if not all the excess cholesterol entering your bloodstream is also exiting your bloodstream. The result is high blood cholesterol, and the accumulation of waxy cholesterol in your arteries.

Doctors use the cholesterol ratio mentioned above, as well as your triglycerides and other factors, to diagnose how at risk you are for developing heart disease.

High blood cholesterol is a condition in which a person's blood cholesterol levels are above 240 mg/dL. It is symptomless and occurs when the cholesterol builds up as plaque in human arteries. With atherosclerosis, which is an excess of cholesterol accumulated in the arteries, your blood has trouble transporting oxygen throughout your body, and less blood to your heart means you're at risk of heart disease. The Centers for Disease Control put the incidence of high blood cholesterol at slightly less than one-fifth of the people in the U.S. over 20 years old.

Researchers know less about cholesterol than they'd like. They don't know why some people have high cholesterol and others have low cholesterol levels.

Genetics and heredity seem to play a part, as does diet and the rate at which an individual metabolizes the cholesterol in his body.

High cholesterol is associated statistically with age, sex, being overweight, and inactivity.

However, none of these are causes. They're associations. Just because you don't exercise does not necessarily mean you'll develop high cholesterol.

For cardiac patients or people who do have high cholesterol, treatment is tricky. For some people, dietary changes, either positive or negative, have little effect on their blood cholesterol levels. For others, they have a noticeable effect.

Talk to your doctor about the best choices for you.

• Both to lower your blood cholesterol level and achieve a more optimal cholesterol ratio, eat a healthy diet. 
• Eat "good" fats, the polyunsaturated and monounsaturated fats.
• Reduce your intake of saturated fats.
• Eliminate trans-fats (hydrogenated oils) from your diet.
  
• Get a fasting blood cholesterol check once every five years.
• Reduce your intake of simple carbohydrates.
• Get plenty of physical activity.
  
• Don't drink too much alcohol.
• If you have high cholesterol, your physician may prescribe statin drugs or other cholesterol medications to lower your cholesterol.
• Keep up with the research on cholesterol.  What we know is always changing.