Popular culture has turned cholesterol into a public enemy, but the fact is we all need some cholesterol. It helps make new cells and keep us healthy. The challenge is to make sure you have the right amount of the right kind of cholesterol in your system. Get the balance wrong, and you’re at risk of developing cardiovascular disease (CVD).

Protect your heart by learning what cholesterol is, how it can damage your cardiovascular system and how to manage your risk.

What Is Cholesterol?

Cholesterol is a type of fat or lipid that circulates in your blood, helping to build cell membranes, aiding in the production of hormones and in the absorption of fat from food. Particles called lipoproteins move cholesterol through your blood. But it’s very easy to have too much cholesterol in your blood, which can lead to artery damage and CVD.

There are three main components of cholesterol you should know about: LDL, HDL and triglycerides.

LDL (low-density lipoprotein): The L could stand for “lousy” cholesterol, because of its potential to damage your cardiovascular system. LDL carries most of the cholesterol in the blood to be stored away for future use.

HDL (high-density lipoprotein): This is the “healthy” cholesterol that carries cholesterol from the body to the liver, where it is eliminated.

Triglycerides: The most common type of fat in your body, triglycerides transport and store fat in the blood. When you eat excess calories, especially sugar and alcohol, they are stored as triglycerides.

How Does Cholesterol Influence Heart Health?

Cholesterol and your heartCholesterol’s components — LDL, HDL, and triglycerides — work together for the healthy functioning of your body. But too much or too little of these fats can spark a destructive process that can lead to cardiovascular disease.

Too much LDL can lead to a buildup of plaques on the walls of blood vessels, causing them to narrow or harden and restrict blood flow. This is known as atherosclerosis (American Heart Association).

Narrowing of the blood vessels that lead to the heart can cause coronary artery disease, angina, and heart attack. When plaques break away from the wall of a blood vessel and block an artery, that’s called a heart attack. Narrowing of the blood vessels leading to the brain can cause stroke.

This video from Khan Academy gives a helpful explanation of how atherosclerosis is dangerous for your heart.

Too little HDL enables harmful LDL to linger in the arteries instead of moving to the liver, where it would naturally be eliminated from the body.

Too many triglycerides increase the likelihood of hardening of the arteries, which raises the risk for heart disease, stroke and heart attack.

Not only does high cholesterol strongly increase your chances of having a heart attack or developing cardiovascular disease, it also increases your chances of developing other serious health problems, such as coronary artery disease, stroke, high blood pressure, diabetes and obesity.

Who Is at Risk for High Cholesterol?

If you eat, you’re at risk of having unhealthy cholesterol levels, a risk that increases significantly when any of the following factors are present. Talk to your doctor if even one of the following risk factors applies to you.3

  • You have an inflammatory disease
  • You have HIV


What Causes High Cholesterol?

Some causes of high cholesterol are beyond your control, such as age, family history and gender. High cholesterol can be hereditary and levels of LDL naturally rise as people get older.

You can’t change your age or family history, but there are risk factors in your life that you can change, including: 

How Do I Know If I Have High Cholesterol?

Your doctor will calculate your level of risk (low, moderate or high) using a specific evaluation tool and factors such as previous heart attack and/or stroke, artery blockages in your neck, arms, or legs, diabetes, age and two or more risk factors, such as smoking, high blood pressure, low HDL, or a family history of CVD.

If none of the above-mentioned factors applies to you, and you are older than 20 years of age, your doctor will decide whether it’s necessary for you to be tested and how often. The blood test is taken after you have fasted overnight or for 10 to 12 hours.5  It measures your total cholesterol, triglycerides, LDL, and HDL levels.  Total cholesterol/HDL (TC/HDL) is a ratio used to measure your cardiovascular risk. TC/HDL is calculated by dividing your total cholesterol number by your total HDL cholesterol number.

What If My Cholesterol Levels are too High?

There are two main tools for managing cholesterol and many patients require both: medication and changes in lifestyle. Making recommended lifestyle changes can improve your cholesterol by 5% to 10%,6 but medications have been shown to lower LDL-cholesterol by 20% to 55%.7 As a result, medication is often required in combination with lifestyle changes, such as quitting smoking and increasing exercise.

Different drugs lower LDL and triglycerides, raise HDL, and reduce the amount of cholesterol absorbed in the digestive system. A patient may take more than one cholesterol-lowering drug at the same time.

Cholesterol-Lowering Drugs 

All patients who already have coronary heart disease or diabetes should be treated with a statin. Statins are safe and effective drugs for lowering cholesterol. Some patients may require the addition of a second medication.

Triglyceride-Lowering Drugs

Drug therapy guidelines for high triglycerides are not as clear-cut as they are for cholesterol. However, fibrates are the drug of choice for lowering triglycerides in the very high range for people whose cholesterol levels are relatively normal. The most potent fibrates can lower triglycerides by 40%. Statins are effective against both cholesterol and triglycerides. Successful treatment requires consistent blood sugar control for people with diabetes and avoidance of alcohol, oral estrogen, and retinoids.

Treatment of Low HDL

The B vitamin niacin is capable of increasing HDL by 30% (and often by an even higher percentage with prolonged treatment). It is the most effective agent for increasing HDL levels.

Medications are commonly prescribed if you are at high risk for CVD, or you are at moderate risk and have additional risk factors. If you’ve been prescribed medication, it’s important to follow the prescription plan your doctor has set up for you. Remember to:

  • Never stop taking your medication just because you are feeling better.
  • Write down any symptoms you may experience so that you can remember to discuss them with your doctor.
  • Keep track of your medication, especially if you are taking multiple pills. A pocket medication card can help.
  • Be on time and consistent with your medication so that it remains effective.


Lifestyle Changes 

For most people, medication alone isn’t enough. Most of your cholesterol comes from the food you eat, but there’s more to managing cholesterol than watching what you eat. Learn more about the most important lifestyle changes and how to get started, eating a healthy diet, losing weight, increasing exercise, quitting smoking and managing diabetes.

Knowing your cholesterol level is an important step to good heart-health. High cholesterol affects almost half of Canadians aged 40 to 59 and more than a quarter of Canadians between the ages of 20 and 39, but many people with high cholesterol have no idea their levels are high.2 Talk to your doctor to see if you should have your cholesterol measured, and for advice on managing your cholesterol.

See a list of printable and downloadable tools to help manage your cholesterol.


  1. Heart Health and Cholesterol Levels of Canadians, 2007 to 2009, Table 1: Health Levels of Lipids in Blood. Canadian Partnership Against Cancer, Statistics Canada.
  2. Health Canada. Canadian Health Measures Survey: Cholesterol and Vitamin D Levels. Statistics Canada, March 23, 2010.
  3. Genest J, McPherson R, Frohlich J, et al. Canadian Cardiovascular Society/Canadian Guidelines for the diagnosis and treatment of dyslipidemia and prevention of cardiovascular disease in the adult: 2009 recommendations. Canadian Journal of Cardiology. 2009; 25(10): 567-579.
  4. Grover SA, Kaouache M, Lowensteyn I. Health outcomes/public policy: preventing cardiovascular disease among Canadians: what are the potential benefits of treating hypertension or dyslipidemia? Canadian Journal of Cardiology. 2008; 24(12).
  5. Fodor J, Boss S. Guideline of Lipid Testing in Adults. Expert Panel for the Ontario Association of Medical Laboratories, 2010.
  6. Anderson, TJ, Grégoire, J., Hegele, R., et al. 2012 CCS Dyslipidemia Guidelines. Canadian Cardiovascular Society, 2012.
  7. Scirica B, Cannon C, Christopher P. Treatment of elevated cholesterol. Circulation. 2005; 111:e360-e363.