Coronary heart disease - Causes 

Causes of heart disease 

CHD Dave's story: high cholesterol

Having high cholesterol can put you at greater risk of heart disease. Dave shares his battle with his cholesterol levels, and talks about how he got to where he is now, successfully managing his condition.

Media last reviewed: 11/11/2013

Next review due: 11/11/2015

Know your blood pressure

The normal range for blood pressure readings is 120/80 to 140/90, although many healthy people have a lower blood pressure than 120/80.

If yours is consistently high, you have a greater risk of developing coronary heart disease and having a stroke.

Ask your GP to check your blood pressure.

Read more about diagnosing high blood pressure.

Why body shape matters

Many doctors believe your waist size is important when assessing weight-related health risks

Coronary heart disease (CHD) is usually caused by a build-up of fatty deposits on the walls of the arteries around the heart (coronary arteries).

The fatty deposits, called atheroma, are made up of cholesterol and other waste substances.

The build-up of atheroma on the walls of the coronary arteries makes the arteries narrower and restricts the flow of blood to the heart muscle. This process is called atherosclerosis. Your risk of developing atherosclerosis is significantly increased if you:

Other risk factors for developing atherosclerosis include:

  • being obese or overweight
  • having a family history of CHD – the risk is increased if you have a male relative with CHD under the age of 55 or a female relative under 65


Cholesterol is a fat made by the liver from the saturated fat that we eat. Cholesterol is essential for healthy cells, but too much cholesterol in the blood can lead to CHD.

Cholesterol is carried in the bloodstream by molecules called lipoproteins. There are several different types of lipoproteins, but two of the main ones are low-density lipoproteins (LDL) and high-density lipoproteins (HDL).

LDL, often referred to as bad cholesterol, takes cholesterol from the liver and delivers it to cells. LDL cholesterol tends to build up on the walls of the coronary arteries, increasing your risk of heart disease.

HDL, often referred to as "good cholesterol", carries cholesterol away from the cells and back to the liver, where it is broken down or passed from the body as a waste product.

In the UK, the government recommends that total cholesterol levels should be:

  • 5mmol/L or less for healthy adults
  • 4mmol/L or less for those at high risk

Levels of low-density lipoprotein (LDL) should be:

  • 3mmol/L or less for healthy adults
  • 2mmol/L or less for those at high risk

An ideal level of high-density lipoprotein (HDL) is above 1mmol/L. A lower level of HDL can increase your risk of heart disease.

Your ratio of total cholesterol to HDL may also be calculated. This is your total cholesterol level divided by your HDL level. Generally, this ratio should be below four, as a higher ratio increases your risk of heart disease.

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High blood pressure

High blood pressure (hypertension) puts a strain on your heart and can lead to CHD.

Blood pressure is measured at two points during the blood circulation cycle:

  • systolic pressure is a measure of your blood pressure as the heart contracts and pumps blood out
  • diastolic pressure is a measure of your blood pressure when your heart is relaxed and filling up with blood

Blood pressure is measured in terms of millimetres of mercury (mmHg).

When you have your blood pressure measured, the systolic pressure is the first, higher number to be recorded. The diastolic pressure is the second, lower number to be recorded.

High blood pressure is defined as a systolic pressure of 140mmHg or more, or a diastolic pressure of 90mmHg or more.

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Smoking is a major risk factor. Carbon monoxide (from the smoke) and nicotine both put a strain on the heart by making it work faster. They also increase your risk of blood clots.

Other chemicals in cigarette smoke damage the lining of your coronary arteries, leading to furring of the arteries. If you smoke, you increase your risk of developing heart disease by 24%.

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While a high blood sugar level doesn't directly increase the risk of developing CHD, it may lead to diabetes, which can more than double your risk of developing CHD.

Diabetes can lead to CHD as it may cause the lining of blood vessels to become thicker, which can restrict blood flow.

Read more about diabetes.


thrombosis is a blood clot within an artery (or a vein). If a thrombosis occurs in a coronary artery (coronary thrombosis), it will cause the artery to narrow, preventing the blood supply from reaching the heart muscle. This increases your chance of having a heart attack.

Coronary thrombosis usually happens at the same place the atherosclerosis is forming.

Page last reviewed: 26/09/2014

Next review due: 26/09/2016


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The 4 comments posted are personal views. Any information they give has not been checked and may not be accurate.

User742371 said on 22 January 2013

Heart Strokes in Youth increased for more information

The percentage of heart strokes in the people are increasing day-by-day especially in the young people because of their food habits. In 1993, the heart strokes were 13% among the people aged below 55 and now the percentage increased to 18%in...

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User363614 said on 09 November 2011

Heart disease is not correlated with cholesterol levels, it is however correlated with elevated blood sugar. Lowering the glycaemic levels of your diet may beneficial, whereas lowering the saturated fat/cholesterol is unlikely to be, and can even be dangerous.

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thiruvelan said on 26 January 2010

Coronary heart disease (CHD) risk factor is high if smoke, high blood pressure, have a high blood, high cholesterol level, and have diabetes.

Coronary artery disease (CAD) or coronary heart disease is a condition in which plaque builds up inside the coronary arteries, which supplies oxygen rich blood to the heart muscles.

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TKes said on 26 November 2009

One of the ways recommended to reduce the risk of a heart attack is to lower your blood cholesterol. But the question is: By how much?

As understand it, a cholesterol of less than 5 is reckoned to be the healthiest. But that doesn't jibe with a lot of evidence that suggests that 5 or less is actually too low for someone who is middle aged or older.

A UK cholesterol and health website, lists a whole bunch of conditions under "the dangers of low cholesterol", which are probably worse than having a heart attack as they cover things like Alzheimers' up to an earlier death, in people with cholesterol levels that are too low. And, by too low, it seems to be talking about levels less than about 6.8

As I am approaching my 50th, I think I'll leave my 6.2 as it is - at least for now.

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