According to the Centres for Disease Control and Prevention (CDC), nearly 86 million U.S. adults aged 20 or older have cholesterol levels exceeding 200 milligrams per deciliter (mg/dL). Total cholesterol is considered high when it exceeds 240 mg/dL.
However, you may not know that you have high cholesterol (also known as hyperlipidemia or dyslipidemia) until you get tested, as this condition often presents no symptoms.
What is cholesterol?
Cholesterol is a type of lipid—a waxy, fat-like substance produced by the liver. It is essential for the formation of:
- cell membranes
- certain hormones
- vitamin D
Cholesterol is insoluble in water, so it cannot travel through the blood on its own. To facilitate cholesterol transport, the liver produces lipoproteins.
Lipoproteins are particles composed of fats and proteins that transport cholesterol and triglycerides—another type of lipid—through the bloodstream. The two main forms of lipoproteins are low-density lipoproteins (LDL) and high-density lipoproteins (HDL).
You may have referred to these as “bad” cholesterol (LDL) and “good” cholesterol (HDL).
LDL cholesterol refers to all cholesterol transported by low-density lipoproteins. If your blood contains an excess of LDL cholesterol, you may be diagnosed with elevated LDL cholesterol levels.
Symptoms of high cholesterol
High cholesterol is often a “silent” condition and generally presents no symptoms.
Many people do not realise they have high cholesterol—or receive treatment for it—until they develop serious complications, such as a heart attack or a stroke. That is why it is important to have your cholesterol levels checked regularly.
If you are 20 years of age or older, ask your doctor if you should undergo a routine cholesterol screening.
Causes and risk factors of high cholesterol
Excessive consumption of foods rich in cholesterol, saturated fats, and trans fats can increase your risk of developing high cholesterol.
Obesity can also increase this risk. Other lifestyle factors that may contribute to high cholesterol include physical inactivity and smoking.
Genetics can also influence your likelihood of developing high cholesterol.
However, high cholesterol is rarely caused by familial hypercholesterolemia, an inherited genetic disorder that prevents the body from eliminating LDL cholesterol. Most adults with this condition have total cholesterol levels exceeding 240 mg/dL and LDL levels exceeding 190 mg/dL.
Other health conditions, such as diabetes and hypothyroidism, can increase your risk of developing high cholesterol and associated complications.
People of all ages, sexes, and ethnicities can develop high cholesterol. Although these risk factors are beyond your control, there are ways to reduce these risks.
LDL cholesterol vs. HDL cholesterol vs. triglycerides
Here’s the difference between the three types of cholesterol:
LDL ‘bad’ cholesterol
LDL cholesterol transports cholesterol to the arteries.
If your LDL cholesterol levels are too high and left untreated, plaque can build up on the walls of your arteries—a condition known as atherosclerosis. This can:
- narrow the arteries
- limit blood flow to tissues and organs
- increase the risk of blood clot formation
If a blood clot blocks an artery in the heart or brain, it can lead to a heart attack or a stroke.
High cholesterol can also cause gallbladder dysfunction, increasing the risk of gallstones.
Complications of atherosclerosis
Atherosclerosis can cause potentially life-threatening complications, such as:
- stroke
- heart attack
- angina or chest pain
- high blood pressure
- peripheral vascular disease
- chronic kidney disease
Learn other ways that high cholesterol can affect your body.
HDL ‘good’ cholesterol
HDL cholesterol essentially works against LDL cholesterol by returning it to the liver for elimination from the body, which prevents the accumulation of cholesterol plaque in the arteries. It reduces the risk of:
- blood clots
- heart disease
- strokes
Triglycerides
Triglycerides are another type of lipid. While your body uses cholesterol to build cells and certain hormones, it uses triglycerides for energy.
Your body converts calories it cannot use immediately into triglycerides, which are stored in fat cells. It uses lipoproteins to circulate triglycerides through the bloodstream.
If you habitually consume more calories than your body can use, your triglyceride levels could become too high. This can increase your risk of developing health problems, including heart disease and stroke.
A doctor can perform a blood test to measure your triglyceride and cholesterol levels.
Cholesterol testing
The CDC recommends having your cholesterol levels checked every 4 to 6 years. If you have a family history of high cholesterol or other risk factors for cardiovascular disease, your doctor may suggest that you undergo cholesterol testing more frequently.
Your doctor will use a test called a lipid profile to measure your levels of:
- total cholesterol (the total amount of cholesterol in your blood, including LDL and HDL cholesterol)
- LDL cholesterol
- HDL cholesterol
- triglycerides
If your total or LDL cholesterol levels are too high, your doctor may diagnose you with high cholesterol. High cholesterol can be dangerous when your LDL levels are excessively high, and your HDL levels are too low.
How to lower cholesterol
If you have high cholesterol, your doctor may recommend lifestyle changes to help lower it.
Most doctors use generalised parameters to determine treatment plans. These parameters can be classified as:
- desirable
- borderline high
- high cholesterol
Your doctor may also prescribe medication to help lower your cholesterol levels. Occasionally, they may refer you to a specialist for additional testing.
Diet
To help you reach and maintain healthy cholesterol levels, your doctor may recommend dietary changes. They might advise you to:
- limit your intake of foods rich in cholesterol, saturated fats, and trans fats
- choose lean protein sources, such as chicken, fish, and legumes
- consume a variety of fibre-rich foods, such as fruits, vegetables, and whole grains
- opt for foods that are baked, roasted, steamed, or grilled
- avoid sugary and pre-packaged food options whenever possible
Foods rich in cholesterol, saturated fats, or trans fats that your doctor might advise you to avoid include:
- red meat, organ meats, egg yolks, and high-fat dairy products
- ultra-processed foods made with cocoa butter or palm oil
- fried foods
- certain baked goods, such as some cookies and muffins
Fish and other foods containing omega-3 fatty acids can help lower your LDL levels.
The takeaway
High cholesterol often presents no symptoms. However, if left untreated, it can cause serious health problems.
A healthcare professional can help you manage your cholesterol levels and, in many cases, prevent complications.
Ask a doctor to check your cholesterol levels, especially if you are over 20. Adopting healthy lifestyle habits—such as exercising and not smoking—along with consuming whole, nutritious foods, will help you take care of your health and manage your cholesterol.