Heart & Stroke Conditions Explained


High Cholesterol

Cholesterol is a type of fat found in your blood.

You need a certain amount of cholesterol for all your body cells and to produce important hormones.

However, if there is too much cholesterol in your blood, it sticks to your artery walls to form atheroma or plaque. Having high cholesterol is one of the risk factors which increase your chances of getting heart disease and stroke.

As a result of this build-up on the artery walls, your arteries become narrowed. This process is called hardening of the arteries or atherosclerosis.


  • If an artery supplying the heart muscle becomes blocked completely, the heart muscle becomes damaged. This is known as a heart attack.
  • If an artery to the brain is completely blocked, it damages the brain. This is called a stroke.


The relationship between cholesterol and heart disease and stroke is complicated but it helps to look at how cholesterol is carried around in the bloodstream.


Know the types of cholesterol, good and bad.

There are two main types of cholesterol – HDL cholesterol (high density lipoprotein) and LDL cholesterol (low density lipoprotein).


  • HDL cholesterol is called good cholesterol or healthy cholesterol, because it mops up cholesterol left behind in your arteries and carries it to your liver where it is broken down and passed out of your body. Regular physical activity can help increase your HDL level.


High levels of HDL cholesterol can protect you against having a heart attack or a stroke.


  • LDL cholesterol travels from your liver through your arteries to other parts of your body. LDL is called bad cholesterol because it sticks to the walls in your arteries – making them narrow. This reduces the blood supply to your heart or brain. Eating too many foods high in saturated fat can raise your LDL cholesterol.


High levels of LDL cholesterol increase your risk of heart disease and stroke.


Related topics: cardiovascular disease, atherosclerosis, heart attack, stroke, healthy eating, be active, quit smoking, high triglycerides, diabetes.


High Cholesterol

High cholesterol does not usually cause symptoms.

Instead, it causes the build up of fatty material on the artery walls and symptoms (below) occur when the artery narrows or becomes blocked.

The type of symptoms depend on where the blockage occurs and include:


  • Angina
  • Acute coronary syndrome
  • Heart attack if the heart is affected
  • Stroke or TIA if the brain is affected
  • Leg pain and intermittent pain when walking if the peripheral arteries are affected.


High Cholesterol

Cholesterol is made in the body mainly by the liver. This is often called blood cholesterol.

The body can produce all the cholesterol it needs and can usually maintain a healthy level of blood cholesterol.

However, sometimes the balance goes wrong and there is an increase in blood cholesterol. This may result from inherited problems or from eating too much saturated (animal) fat or too many foods from the top shelf of the Food Pyramid.

Some foods such as eggs, liver and shellfish contain cholesterol. However, the amount of cholesterol in these foods does not greatly affect the amount of cholesterol in your blood. You can eat foods that contain cholesterol in moderation as part of a healthy varied diet.

If you do not have a high blood cholesterol level, you can eat up to 7 eggs a week. However if you have been diagnosed with a high cholesterol level, you may be advised to eat less eggs, depending on your diet.


High Cholesterol

You should have a regular blood pressure and cholesterol check with your doctor.

And for a healthy cholesterol and good heart health, it’s also important to:


  • Eat more fruit and vegetables and wholegrain foods
  • Eat less fatty foods
  • Eat fish twice a week including oily fish
  • If you smoke, try to stop
  • Be a healthy weight
  • Be more physically active for at least 30 minutes 5 days a week
  • Drink less alcohol
  • Learn to relax, de-stress – take time out for yourself.


High Cholesterol

Your cholesterol can be measured by your doctor, who knows your family history.

If a family member has high cholesterol, heart disease or has had a stroke, it’s really important you ask your doctor to do this test. You can do this on any visit to your doctor.

If your results show a blood cholesterol level greater than 5 mmol/l (the measurement used for cholesterol levels), or your doctor is concerned about your HDL (good) or LDL (bad) cholesterol, he or she will arrange for another test. You will need to fast for 12 hours to get more information on your HDL and LDL cholesterol.

Have you already have had a heart attack, bypass surgery or angioplasty? If so, it is very important that you keep your LDL at or below 1.8 mmol/l. Your doctor will most likely suggest medication together with healthy eating and other lifestyle changes, as outlined in our booklets and in our Ways To Live Life Better articles.

Should you need to change any aspects of your cholesterol levels, your doctor will advise you on changes in lifestyle and may recommend medication. If you are prescribed medication, it is important that you follow the instructions carefully.


Cholesterol Healthy levels mmol/l
Total cholesterol Less than 5
LDL cholesterol Less than 3
HDL cholesterol More than 1
People with established heart disease/diabetes/other risk
Total cholesterol Less than 4.5
LDL cholesterol Less than 1.8


High Cholesterol

To treat cholesterol, you need to take steps to live life better, to get active, lose weight and to eat healthily.

Here’s a list of things you can do and see our articles Ways To Live Life Better for more practical tips and inspiration.


  • Get down to a healthy weight – being overweight means your heart has to work harder to pump blood around the body.
  • Be more physically active every day.
  • Eat fish twice a week including oily fish
  • Eat more fruit and vegetables.
  • Eat more wholegrain varieties of cereals, breads, pasta and rice. Choose jacket potatoes.
  • Choose lean meats. Trim fat off meat and skin off chicken. Drain oil from cooked dishes containing minced meat.
  • Choose low-fat dairy products.
  • Choose low-fat spreads made from sunflower or olive oil.
  • Choose less foods from the top shelf of the Food Pyramid.
  • Use low-fat healthy ways of cooking, like grilling or oven-baking, instead of frying.


What if I have low HDL?

If your blood test showed that your HDL cholesterol is below the recommended levels, you will need to increase this level to reduce your risk of heart disease and stroke.

You can increase the healthy HDL levels by:



Your doctor may also prescribe medication to raise your HDL levels.

Support for You

High Cholesterol

The Irish Heart Foundation offers a range of free support services to those affected by heart disease or stroke that can greatly improve their quality of life. These include support groups, physical exercise classes, therapy sessions and more.

For more information on these supports, see our Patient Supports page.

If you have any questions about heart disease or stroke, you can also call the Irish Heart Foundation’s Nurse Support on (01) 668 5001 to speak to a nurse specialist who will answer your questions, and give you guidance and reassurance.


High Cholesterol

Read our resources for further information:

  • View our guide to A Healthy Cholesterol to reduce your risk of heart disease and stroke
  • Fats Of Life magazine, this will show you the difference in fats in foods and which ones to eat and avoid.
  • Food Shopping Card will help you make smarter choices and demystify food labels in the supermarket.
  • Food Diary – keep on track with our special food diary.
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