Among the many functions of cholesterol are making hormones, vitamin D, and bile acids, which help digest fats. Cholesterol is a waxy substance in the blood and in the body cells. However, having too much cholesterol in the blood can increase your risk of heart disease and stroke. As a result of excess cholesterol building up in the arteries, plaques can form and narrow or block blood flow. This condition is known as atherosclerosis.
There are two main types of cholesterol: low-density lipoprotein (LDL) and high-density lipoprotein (HDL). Because LDL carries cholesterol from the liver to the tissues and deposits it in the arteries, it is often called “bad” cholesterol. HDL is often known as the “good” cholesterol because it carries cholesterol back from the tissues to the liver and can remove it from the arteries. The ratio of LDL to HDL is important for determining your heart disease risk. Low HDL levels, high LDL levels, or both can increase the risk.
A type of fat related to cholesterol is triglycerides. Triglycerides are stored in fat cells and are used to provide energy for the body. However, when combined with a high level of LDL or a low HDL, having a high triglyceride level can also increase the risk of heart disease.
Some people inherit a condition called familial hypercholesterolemia, which causes very high levels of LDL cholesterol and increases the risk of early heart disease. High cholesterol can be caused by a combination of genetic and lifestyle factors. The body can also produce or remove triglycerides or cholesterol based on genetic factors.
Lifestyle factors that can contribute to high cholesterol include:
Eating a diet high in saturated fats, trans fats, cholesterol, and refined carbohydrates
Being physically inactive or sedentary
Being overweight or obese
Smoking tobacco or being exposed to secondhand smoke
Drinking too much alcohol
Having certain medical conditions, such as diabetes, hypothyroidism, kidney disease, or liver disease
Taking certain medications, such as steroids, oral contraceptives, or hormone replacement therapy
High cholesterol does not usually cause any symptoms by itself. However, over time, it can lead to symptoms and complications of heart disease and stroke, such as:
Chest pain or angina
Shortness of breath
Irregular heartbeat or arrhythmia
Heart attack
Stroke
Peripheral artery disease (reduced blood flow to the limbs)
Carotid artery disease (reduced blood flow to the brain)
Some people with very high cholesterol levels may develop visible signs, such as:
Xanthelasma (yellowish patches on the eyelids)
Arcus senilis (grayish ring around the cornea)
Xanthomas (fatty deposits under the skin)
Performing a blood test called a lipid profile or lipid panel is the only way to diagnose high cholesterol. The test measures total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides levels in the blood. Usually, you need to fast for 9 to 12 hours prior to taking the test.
Age, gender, family history, and other risk factors for heart disease are considered as factors in interpreting the test results. It is desirable for adults to have a total cholesterol level below 200 mg/dL, an LDL cholesterol level below 100 mg/dL, a HDL cholesterol level above 60 mg/dL, and a triglyceride level below 150 mg/dL. Total cholesterol levels are 200-239 mg/dL, LDL cholesterol levels are 130-159 mg/dL, and triglycerides are 150-199 mg/dL. High levels of total cholesterol are 240 mg/dL and above, LDL cholesterol is 160-189 mg/dL, HDL cholesterol is below 40 mg/dL (men) and triglycerides are 200-499 mg/dL. LDL cholesterol levels above 190 mg/dL and triglycerides above 500 mg/dL are very high.
The cholesterol levels of children and adolescents should also be checked between the ages of 9 and 11 as well as between the ages of 17 and 21. Total cholesterol levels should be below 170 mg/dL for children and adolescents, LDL cholesterol levels should be below 110 mg/dL, and HDL cholesterol levels should be above 45 mg/dL. Total cholesterol levels should be between 170-199 mg/dL, and LDL cholesterol levels should be between 110 and 129 mg/dL. LDL cholesterol levels above 130 mg/dL and total cholesterol levels above 200 mg/dL are considered high.
Various treatment options are available for high cholesterol, depending on the level of risk for heart disease and stroke. The main goals of treatment are to lower the LDL level, raise the HDL level, and reduce the triglyceride level.
Dietary changes include reducing saturated fats, trans fats, cholesterol, and refined carbohydrates, consuming more fiber, fruits, vegetables, whole grains, nuts, seeds, and fish, and moderately drinking alcohol. Additionally, they recommend being physically active for 150 minutes per week, losing weight if overweight or obese, quitting smoking, and managing stress.
There are several medications that reduce cholesterol production or absorption in the liver or intestines, including statins, bile acid sequestrants, cholesterol absorption inhibitors, and PCSK9. Aside from fibrates, niacin, and omega-3 fatty acids, they include drugs that lower triglycerides or raise HDL levels. The dose and choice of medication depend on the individual's risk factors, response to treatment, and side effects.
This treatment is reserved for people with very high cholesterol levels caused by a genetic condition or who don't respond to other treatments. It involves removing part of the liver or implanting a device that filters the blood.
The best way to prevent high cholesterol is to adopt a healthy lifestyle from an early age. This includes:
Eating a balanced diet that is low in saturated fats, trans fats, cholesterol, and refined carbohydrates; high in fiber, fruits, vegetables, whole grains, nuts, seeds, and fish; and moderate in alcohol
Being physically active for at least 150 minutes per week
Maintaining a healthy weight
Quitting smoking
Limiting stress
Getting regular check-ups and screenings for cholesterol and other risk factors for heart disease
It is important for the body to have cholesterol, but too much can cause serious health problems for the heart and blood vessels. If you understand the causes, symptoms, diagnosis, treatment, and prevention of high cholesterol, you can protect yourself and your health.
