Cholesterol is a fatty substance that our bodies need to function. You need cholesterol to form cell membranes, many hormones and bile acids (which digest fat). But too much cholesterol can hurt you. When there's too much cholesterol in your blood, it can build up on the inside walls of your arteries and increase your risk of heart disease and stroke.

There are two main types of cholesterol: low-density lipoprotein (LDL) cholesterol (the "bad" cholesterol) and high-density lipoprotein (HDL) cholesterol (the "good" cholesterol).

A low LDL cholesterol level is considered good for your heart health. High levels of LDL cholesterol are linked to atherosclerosis.

Atherosclerosis is the hardening of the arteries. It occurs when fat, cholesterol, and other substances build up in the walls of arteries and form hard structures called plaques.

Atherosclerosis affecting the heart is called coronary artery disease, and it can cause a heart attack. When atherosclerosis blocks arteries that supply blood to the brain, it can cause a stroke.

A high LDL cholesterol level and diabetes, risk factors for coronary artery disease include:

♦ Being a male older than 45

♦ Being a female older than 55

♦ Being a female with premature menopause

♦ Having a family history of premature coronary artery disease (a father or brother younger than 55 with coronary artery disease or a mother or sister younger than 65 with coronary artery disease)

♦ Smoking cigarettes

♦ Having high blood pressure

♦ Not having enough good cholesterol (high density lipoprotein or HDL)

You may help to prevent high cholesterol by staying on a healthy diet and exercising daily. A diet high in saturated and trans fats raises LDL cholesterol. Avoid high-fat foods (eggs, fatty red meats, palm or coconut oil, dairy products made with whole milk). Instead eat more fresh fruits and vegetables, whole-grain breads and cereals, and low-fat dairy products.

Cholesterol levels should be measured at least once every five years in everyone over age 20. The screening test that is usually performed is a blood test called a lipid profile. Experts recommend that men ages 35 and older and women ages 45 and older be more frequently screened for lipid disorders.