What is cholesterol?

Cholesterol is a type of fat (lipid) and is an essential nutrient your body needs for many important functions, such as producing new cells. If you eat too many foods high in saturated fat and cholesterol or you have an inherited condition, the cholesterol levels in your blood may climb to unhealthy levels. This increases your risk for hardening of the arteries, or atherosclerosis , and can lead to life-threatening illnesses, such as coronary artery disease (CAD), heart attack , or stroke .

Your body gets cholesterol from two sources: from the foods you eat and from your liver. Although many foods contain cholesterol, your liver actually produces up to 80% of what you need.

What is high cholesterol?

A blood test can determine if you have high cholesterol .

• A total cholesterol level of less than 200 mg/dL (5.17 mmol/L) is desirable.
• 200 mg/dL to 239 mg/dL (5.17 mmol/L to 6.18 mmol/L) is considered borderline-high cholesterol.
• 240 mg/dL (6.21 mmol/L) or higher is considered high cholesterol.

What are LDL and HDL cholesterol and lipoproteins?

Cholesterol travels through your blood attached to a protein. This cholesterol-protein package is called a lipoprotein. Lipoproteins are either high density, low density, or very low density, depending on how much protein there is in relation to fat.

• Low-density lipoprotein cholesterol (LDL) is called "bad" cholesterol because it can cause cholesterol buildup and blockage of your arteries. blocked artery .) LDL is mostly fat with only a small amount of protein. By lowering LDL cholesterol, you can reduce your risk of atherosclerosis, heart attack, stroke, and other complications.
  • An LDL level of less than 100 mg/dL (less than 2.6 mmol/L) is considered optimal.
  • An LDL level of 100 to 129 mg/dL (2.6 to 3.35 mmol/L) is considered near optimal or above optimal.
  • An LDL level of 130 to 159 mg/dL (3.35 mmol/L to 4.10 mmol/L) is considered borderline high.
  • An LDL level of 160 to 189 mg/dL (4.12 to 4.88 mmol/L) is considered high.
  • An LDL level of 190 and above (4.90 mmol/L and greater) is considered very high.
• High-density lipoprotein cholesterol (HDL) is sometimes called "good" cholesterol because it helps prevent cholesterol from building up in your arteries. It is mostly protein with only a small amount of fat. HDL cholesterol helps clear the bad cholesterol from the body by picking up leftover cholesterol from the bloodstream and carrying it back to the liver for disposal. If you are at risk for heart disease, it may be beneficial to raise your HDL cholesterol levels. Low HDL cholesterol increases the risk of coronary artery disease. High levels of HDL appear to help protect against atherosclerosis, heart attack, stroke, and other complications.
  • An HDL level of 60 mg/dL (1.56 mmol/L) or higher is desirable. An HDL level over 60 mg/dL reduces the risk of heart disease, even if LDL or total cholesterol is high.
  • An HDL level of 40 to 60 mg/dL (1.04 to 1.56 mmol/L) is considered acceptable.
  • An HDL level below 40 mg/dL (below 1.04 mmol/L) is considered low. Low HDL is considered a major risk factor for coronary artery disease in people who also have high total cholesterol levels.
• Triglycerides/very low-density lipoprotein cholesterol (VLDL) . Triglycerides are another type of fat that is carried in the blood by very low-density lipoproteins. Only a small amount of triglycerides is normally found in the blood; most are stored in fat tissue. VLDL is similar to LDL cholesterol in that it contains mostly fat and not much protein. A high triglyceride level along with a high LDL cholesterol also can increase the risk of heart attack.
  • A triglyceride level of 150 to 199 mg/dL is considered borderline high.
  • A triglyceride level of 200 mg/dL is considered high.

What causes high cholesterol?

Several factors can cause high cholesterol. Some risk factors can be controlled; others can't.

• Controllable risk factors include some medical conditions, such as diabetes and hypothyroidism , and diet. Being overweight, smoking, not exercising, and eating a diet high in saturated fat and cholesterol can cause high LDL, low HDL, and increased triglycerides.
• Uncontrollable risk factors include a genetic condition called a lipid disorder , which can cause very high cholesterol levels in your blood. Your age and gender are other risk factors you cannot control. After age 20, cholesterol levels naturally begin to rise. Men have higher cholesterol levels than women until women reach age 50 or so, when their cholesterol levels rise. After puberty, women have higher levels of HDL ("good") cholesterol than men.

There are also secondary causes of high cholesterol, such as medications and medical conditions.

Will I have symptoms of high cholesterol?

Generally, high cholesterol is a "silent" condition that rarely causes its own symptoms. As a result, many people do not realize that they have high cholesterol.

You may, however, have symptoms from a serious illness caused by high cholesterol, such as atherosclerosis, stroke, or peripheral vascular disease . Atherosclerosis is a narrowing of your arteries that can lead to coronary artery disease (CAD). Unfortunately, by the time you feel the symptoms of CAD, such as chest pain, the arteries in your body are usually severely diseased already. Your first symptom of high cholesterol could be a heart attack or a stroke.

Inherited forms of high cholesterol, such as familial hypercholesterolemia, can cause physical signs that you or your doctor may notice. The most common is the formation of xanthomas, which are cholesterol deposits below the skin.

How will a health professional diagnose my cholesterol?

A doctor, nurse practitioner, or physician's assistant will use one of two blood tests to check your cholesterol:

• A nonfasting cholesterol test will show your total cholesterol and high-density lipoproteins (HDL, or "good" cholesterol).
• A fasting cholesterol test, called a lipid profile or a lipoprotein analysis, will measure your LDL ("bad"), HDL, and total cholesterol. It will also measure very low-density lipoproteins (VLDL).

Your doctor may start with a nonfasting cholesterol test and then recommend a lipid profile, based on your results.

How can I lower my cholesterol?

There are two basic ways of lowering your cholesterol: modifying your lifestyle or taking medications. Your doctor may first recommend lifestyle changes, such as modifying your diet, quitting smoking, losing weight, and exercising.

If you cannot lower your cholesterol to safe levels with lifestyle changes, your doctor may prescribe medications along with your new diet and exercise plan. The goal in either case is to lower your LDL ("bad") cholesterol, raise your HDL ("good") cholesterol, and lower triglycerides.

Treatment for high cholesterol is based on your risk of developing coronary artery disease (CAD) or whether you already have CAD or conditions equally as serious. Your cholesterol level will guide your treatment.

If you have a high risk for CAD or already have CAD, you will probably benefit more from medications than people who have a lower risk. ¹ If you have a lower risk, lifestyle changes may be more appropriate and cost-effective. Risk factors for CAD include high blood pressure, smoking, low HDL cholesterol, a family history of heart disease, and being 45 years of age or older for men or 55 or older for women.

What lifestyle changes will I have to make?

Dietary therapy, combined with regular exercise and weight loss, if needed, is the cornerstone of treatment. Diets designed to lower your cholesterol are called dietary therapy or medical nutrition therapy because this approach is more than just "going on a diet." Your doctor and a professional dietitian will give you specific advice about eating a balanced diet, including how much total fat and saturated fat you may eat every day.

As a part of your dietary therapy, you will learn that not all fats are created equal. There are several different types of fat, each of which has a different effect on your cholesterol.

Exercising and losing weight, if you are overweight, are also critical. They can increase your "good" HDL cholesterol and lower your "bad" LDL cholesterol and triglycerides. Losing weight can also help lower high blood pressure . Most health experts recommend that you exercise for a minimum of 30 to 45 minutes most days of the week.

Another critical lifestyle change you can make is to stop smoking cigarettes. Smoking decreases "good" HDL cholesterol and changes LDL cholesterol so that it promotes the buildup of deposits on the walls of your coronary arteries. It also increases the risk of heart disease.