High blood cholesterol is a common medical condition in both men and women, and the risk increases as we age. High cholesterol levels are a risk factor for heart disease and having a heart attack. Like high blood pressure, high levels of cholesterol have no symptoms early on.
Cholesterol abnormalities may also present without major elevations in total blood cholesterol. In what is called the Metabolic Syndrome, a cluster of disorders of the body's metabolism there is an abnormally low HDL cholesterol, higher triglyceride, mild to very significant high blood pressure and excess body weight (especially around the waist). Metabolic Syndrome makes you more likely to develop diabetes, heart disease or stroke.
Cholesterol is a fat-like substance found in the blood and produced by the liver. It is also found in animal tissue and is present only in foods from animal sources such as whole-milk dairy products, meat, fish, poultry, animal fats and egg yolks. Some individuals have high cholesterol because of a family history (genetic predisposition). Too much cholesterol can build up in artery walls and cause narrowing so that blood flow is constricted or blocked.
A cholesterol reading is taken from a simple blood test. A normal cholesterol reading is usually defined as less than 200 mg/dL, which is a measurement of your total cholesterol, including high-density liproprotein (HDL or good cholesterol), low-density lipoprotein (LDL or bad cholesterol) and fat-linked cholesterol (measured as triglyceride). Cholesterol levels are measured in milligrams (mg) of cholesterol per deciliter (dL) of blood. A total cholesterol reading above 205 mg/dL is a sign of cholesterol higher than average for Americans.
A cholesterol test is a key component of good medical practice that is taken to monitor your health, along with your blood pressure, weight and blood glucose levels. The National Cholesterol Education Program guidelines recommend that everyone 20 years of age and older have their cholesterol level measured once every five years. If your cholesterol is high, your physician may monitor your cholesterol levels more frequently.
Some people are confused by the terms "HDL" and "LDL." HDL, the good cholesterol, carries cholesterol away from the arteries and to the liver, where it is disposed of. Higher levels of HDL, greater than 60 mg/dL, can protect you from a heart attack.
High levels of LDL or bad cholesterol, on the other hand, can lead to atherosclerosis — a build-up of atheromas or plaque (fatty deposits) within arterial walls. Atheromas contain cholesterol, triglycerides and phospholipids, along with calcium and blood-clotting products, all of which are normally found in circulating blood. The build-up of atheromas can cause a narrowing or blockage in an artery that reduces blood flow. An LDL reading of less than 100 mg/dL is considered best for optimum health.
Triglycerides are a form of fat in the blood. High triglyceride levels are often associated with other factors such as low HDL (good) cholesterol and diabetes, which can lead to heart disease. A triglyceride level less than 150 mg/dL is considered normal. A reading of 500 mg/dL and above is considered very high.
High cholesterol levels and abnormalities of HDL, LDL and triglycerides can be seen at any age. The risk for having cholesterol abnormalities increases as we age. These abnormalities can be caused by lifestyle choices, such as eating too much saturated fat in animal products, tobacco use, inactivity and obesity.
Many individuals have a family history or genetic predisposition to developing high cholesterol that can be managed with a combination of diet, exercise and cholesterol-reducing drugs (see Treating High Cholesterol).