What is cholesterol?
Cholesterol is a waxy substance your body uses to protect nerves, make cell tissues, and produce certain hormones. Your liver makes all the cholesterol your body needs. Your body also gets cholesterol directly from the food you eat (such as eggs, meats, and dairy products)..
Too much cholesterol can have negative impacts on your health.
What are the types of cholesterol?
There are two main types of cholesterol, one good, and the other bad. Having too much ‘bad’ cholesterol can cause problems with your health. Cholesterol is carried in your blood by proteins. When cholesterol and proteins combine, they’re called lipoproteins.
High-density lipoproteins or HDL is called ‘good’ cholesterol. This is because it gets rid of the ‘bad’ cholesterol from your blood. It takes cholesterol that you don’t need back to the liver. The liver breaks it down so it can be passed out of your body.
Non-high-density lipoproteins or non-HDL is called ‘bad’ cholesterol. This is because when there is too much of it, it can build up inside the walls of the blood vessels. This clogs them up causing narrowing of the arteries which increases your risk of having a heart attack or stroke.
You may have also heard ‘bad’ cholesterol is called ‘LDL’ cholesterol. This was previously used as the main measure of bad cholesterol but we now know that other forms of non-HDL cholesterol are also harmful.
What is the difference between “good” cholesterol and “bad” cholesterol?
Low-density lipoprotein (LDL) is often called “bad” cholesterol. It delivers cholesterol to the body. High-density lipoprotein (HDL) is often called “good” cholesterol. It removes cholesterol from the bloodstream.
This explains why too much LDL cholesterol is bad for the body, and why a high level of HDL cholesterol is good. For example, if your total cholesterol level is high because of a high LDL level, you may be at higher risk of heart disease or stroke. But, if your total cholesterol level is high only because of a high HDL level, you’re probably not at higher risk.
Triglycerides are another type of fat in your blood. When you eat more calories than your body can use, it turns the extra calories into triglycerides.
Changing your lifestyle (diet and exercise) can improve your cholesterol levels, lower LDL and triglycerides, and raise HDL.
What should my cholesterol levels be?
Your ideal cholesterol level will depend on your risk for heart disease.
- Total cholesterol level – less than 200 is best but depends on your HDL and LDL levels
- LDL cholesterol levels – less than 130 is best, but this depends on your risk for heart disease
- HDL cholesterol levels – 60 or higher reduces your risk for heart disease
- Triglycerides – less than 150 milligrams per deciliter (mg/dl) is best
Symptoms of high cholesterol
Often, there are no symptoms that specifically relate to cholesterol. So you could have cholesterol and not know it.
If you have cholesterol, your body may store the extra cholesterol in your arteries. Your arteries are blood vessels that carry blood from your heart to the rest of your body. The buildup of cholesterol in your arteries is known as plaque. Over time, plaque can become hard and make your arteries narrow. Large deposits of plaque can completely block an artery. Cholesterol plaques can also split open, leading to the formation of a blood clot that blocks the flow of blood.
If an artery that supplies blood to the muscles in your heart becomes blocked, you could have a heart attack. If an artery that supplies blood to your brain becomes blocked, you could have a stroke.
Many people don’t discover that they have cholesterol until they suffer one of these life-threatening events.
What causes high cholesterol?
Anyone can get cholesterol, and it can be caused by many different things. Some things you can control like lifestyle habits, others you can’t. As long as you take care of the things you can control, you’ll help lower your risk.
Things that cause cholesterol you can control:
- eating too much-saturated fat
- not being active enough
- having too much body fat, especially around your middle.
Smoking can lead to cholesterol levels, and the build-up of tar it causes in your arteries makes it easier for cholesterol to stick to your artery walls.
If you are overweight or have diabetes, you are at greater risk of having cholesterol.
Things that cause high cholesterol you can’t control:
- getting older
- if you are male or female
- ethnic background
- Familial Hypercholesterolaemia (FH), a form of cholesterol you are born with
- kidney or liver disease
- an underactive thyroid gland
How is cholesterol measured?
Blood cholesterol levels are measured using a simple blood test. Your GP or practice nurse will take a blood sample, usually by pricking your finger or you might be asked to go for a blood test at your local hospital.
Your blood is then checked for levels of good (HDL) cholesterol, bad (non-HDL) cholesterol and triglycerides, as well as getting a total cholesterol result.
Cholesterol and triglycerides are measured in units called millimoles per liter of blood, usually shortened to ‘mmol/Litre’ or ‘mmol/L’. Generally speaking, for a healthy heart the aim is to have a low non-HDL level and a higher HDL level.
If you have been told you have a high cholesterol level, you have too much ‘bad’ cholesterol in your bloodstream which increases your risk of having a heart attack or stroke. But a high level of ‘good’ (HDL) cholesterol can help keep that ‘bad’ (non-HDL) cholesterol in check.
What is a healthy or normal cholesterol level?
There is no specific target cholesterol level because your doctor is looking at your overall risk of developing heart and circulatory diseases. Your risk is increased if you have high cholesterol as well as other risk factors, such as:
- high blood pressure
- being physically inactive
- being overweight
- having diabetes
- family history of premature coronary heart disease (before 55 for men and before 65 for women)
- being of South Asian origin
The more risk factors you have, the higher your risk of developing a heart or circulatory diseases such as a heart attack, stroke or vascular dementia.
How can I lower my cholesterol levels?
- Eat a healthy balanced diet, low in saturated fat
- Get active
- Quit smoking
Find out more about living a healthy lifestyle and simple swaps you can make to help reduce your cholesterol.
Living with high cholesterol
If you have high cholesterol, you are twice as likely to develop heart disease. That is why it is important to have your cholesterol levels checked, especially if you have a family history of heart disease. Working to decrease your LDL “bad cholesterol” through a good diet, exercise, and medication can make a positive impact on your overall health.
Questions to ask your doctor
- Am I at risk for heart disease?
- How often should I get my cholesterol tested?
- What are my cholesterol levels? What do they mean?
- What lifestyle changes do I need to make to help improve my cholesterol levels and heart health?
- Is there a chance that I’ll need cholesterol-lowering medicine?
- What are the risks and benefits of taking this medicine?
Preventing high cholesterol
People who wish to reduce their cholesterol levels or maintain a suitable level can make four major lifestyle decisions.
- eat a heart-healthy diet
- regularly exercise
- avoid smoking
- achieve and maintain a healthy weight
These actions will reduce the risk of coronary heart disease and heart attack.
Since 2013, guidelines on reducing or preventing cholesterol have focused on addressing lifestyle risks, even at a young age.
Since 2018, new guidelines published in the Journal of the American College of Cardiology also urged doctors also to discuss with individuals the following factors that may increase a person’s risk:
- family history and ethnicity
- certain health conditions that increase the risk of cholesterol, such as chronic kidney disease or chronic inflammatory conditions
Taking these factors into consideration will lead to a more personalized approach to the treatment and prevention of cholesterol levels.
Complications of high cholesterol
In the past, people have aimed to reduce cholesterol to a target level, for instance, below 100 mg/ dL, but this is no longer the case.
Randomized, controlled clinical trials have not produced enough evidence to support treatment to a specific target.
However, some physicians may still use targets to help guide therapy.
The 10-year risk of a heart attack
Cholesterol levels play a major part in an individual’s risk of having a heart attack within the next 10 years.
The National Heart, Lung, and Blood Institute provide an online calculator of cardiovascular risk.
Using research evidence, it weighs the risk according to these factors:
- cholesterol levels
- smoking status
- blood pressure
Guidelines published in 2018 consider this calculator and essential tool for assessing cholesterol levels and their risk.
Frequently Asked Questions About High Cholesterol
What Is Cholesterol?
Cholesterol is a waxy, fat-like substance that occurs naturally in all parts of the body and is made by the liver. Cholesterol also is present in the foods we eat. People need cholesterol for the body to function normally. Cholesterol is present in the cell walls or membranes everywhere in the body, including the brain, nerves, muscles, skin, liver, intestines, and heart.
Why Should I Be Concerned About Cholesterol?
Too much cholesterol in your body means that you have an increased risk of getting cardiovascular diseases such as heart disease. If you have too much cholesterol in your body, the cholesterol can build up on the walls of the arteries that carry blood to your heart. This buildup, which occurs over time, causes less blood and oxygen to get to your heart. This can cause chest pain and heart attacks.
What’s the Difference between “Good” and “Bad” Cholesterol?
HDL (high-density lipoprotein) cholesterol is known as good cholesterol. HDL takes the bad cholesterol out of your blood and keeps it from building up in your arteries. LDL (low-density lipoprotein) cholesterol is known as bad cholesterol because it can build up on the walls of your arteries and increase your chances of getting cardiovascular disease. When being tested for cholesterol, you want a high HDL number and a low LDL number.
How Much Cholesterol Is Too Much?
Doctors recommend your cholesterol stay below 200. Here is the breakdown:
Total Cholesterol – Category
Less than 200 – Desirable
200-239 – Borderline High
240 and above – High
LDL Cholesterol LDL – Cholesterol Category
Less than 100 – Optimal
100-129 – Near optimal/above optimal
130-159 – Borderline high
160-189 – High
190 and above – Very high
HDL (good) cholesterol protects against heart disease, so for HDL, higher numbers are better. A level of less than 40 is low and is considered a major risk factor because it increases your risk for developing heart disease. HDL levels of 60 or more help to lower your risk for heart disease.
Triglyceride levels that are borderline high (150-199) or high (200 or more) may require treatment in some people.
Can I Lower My Risk for Heart Disease If I Lower My Cholesterol?
Your risk for heart disease is lower when you have low total cholesterol and low LDL.
What Makes My Cholesterol Levels Go Up?
Eating foods such as meats, whole milk dairy products, egg yolks, and some kinds of fish can make your cholesterol levels go up. Being overweight can make your bad cholesterol go up and your good cholesterol go down. Also, after women go through menopause, their bad cholesterol levels tend to go up.
What Can I Do To Lower My Cholesterol Levels?
You can lower your cholesterol levels by making changes to your lifestyle. Here are some tips.
- Eat foods with less fat, saturated fat and cholesterol.
- Take off the skin and fat from meat, poultry, and fish.
- Broil, bake, roast, or poach instead of frying foods.
- Eat lots of fruits and vegetables every day.
- Eat lots of cereals, bread, rice, and pasta made from whole grains, such as whole-wheat bread or spaghetti.
- Get lots of exercises every day. Talk to your doctor about what are the safest and best ways for you to exercise.
- Lose weight if you are overweight.
- Stop smoking.
- Take your high blood cholesterol medication as prescribed by your doctor.
What Medications Are Used to Treat High Cholesterol?
Cholesterol-lowering drugs include:
- Bile-acid resins
- Fibric acid derivatives
- Cholesterol-lowering medicine is most effective when combined with a low-cholesterol diet.
If a Product’s Package Reads “Low Cholesterol,” Does That Mean That The Product Is Low in Fat and Safe To Eat?
Not necessarily. Numerous foods marked “low cholesterol” can contain oils that may be high in saturated fats, which are not considered healthy. In addition, unsaturated fats like vegetable oil also can be high in calories. The total amount of fat in your diet should be kept to about 20-30 percent of your daily intake.
At What Age Should People Begin Having Their Cholesterol Checked?
It is important to have your cholesterol level checked when you are young, since clogging of the arteries (atherosclerosis) is a gradual process that takes many years. Total cholesterol should be measured at least every five years starting at age 20.
Note: If you have high cholesterol and your doctor has told you there may be an underlying genetic cause, you may want to have your children, under age 20, get their cholesterol levels tested. Talk to your children’s health care providers about cholesterol testing.