Coronary Heart Disease: Causes, Risk Factors and Prevention
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Reviewer participation may vary by guide. Checked against Cambridge IGCSE Biology 0610 (2026–2028); last reviewed August 2026.
Key concept
Coronary heart disease (CHD) occurs when fatty deposits (atherosclerosis) narrow the coronary arteries, reducing blood flow and oxygen supply to the heart muscle. Risk factors include a high-fat diet, smoking, lack of exercise, obesity, genetic predisposition and stress.
CHD is one of the few medical conditions the Cambridge 0610 syllabus requires in detail. Questions test whether you understand the mechanism (artery narrowing reducing blood supply) rather than just the risk factors.
How coronary heart disease develops
Coronary arteries supply the heart muscle with oxygenated blood. Over time, fatty deposits including cholesterol can build up in the artery wall, forming plaques. This process is atherosclerosis. The plaque narrows the lumen, reducing blood flow through the coronary artery.
With reduced blood supply, the heart muscle receives less oxygen and glucose. If a coronary artery becomes completely blocked: often when a blood clot forms on a plaque: part of the heart muscle is deprived of oxygen and dies. This is a heart attack (myocardial infarction).
Damages artery lining, making plaque formation more likely; carbon monoxide reduces oxygen-carrying capacity
Lack of exercise
Contributes to obesity and higher blood pressure
Obesity
Associated with higher cholesterol and blood pressure
Genetic predisposition
Family history increases risk regardless of lifestyle
Stress and high blood pressure
Damages artery walls over time
Treatment and prevention
Prevention focuses on lifestyle changes: reducing saturated fat intake, regular exercise, stopping smoking and maintaining a healthy body mass. Medical treatments include statins to lower blood cholesterol and stents: wire mesh tubes inserted into narrowed coronary arteries to hold them open and restore blood flow.
In severe cases, a coronary bypass operation grafts a blood vessel from another part of the body to bypass the blocked section, restoring blood supply to the heart muscle.
Try a focused question (4 marks)
Explain how a diet high in saturated fat may lead to a heart attack.
Show the answer and marking guidance
A high saturated fat diet raises blood cholesterol levels.
Cholesterol and fatty deposits build up in the walls of coronary arteries (atherosclerosis).
The lumen narrows, reducing blood flow to the heart muscle.
If the artery becomes fully blocked, part of the heart muscle is deprived of oxygen and dies (heart attack).
Original Cambridge-style practice written for this site. It is not an official Cambridge past-paper question.
Common mix-ups to avoid
Check these points against your own answer before moving on.
Saying fat blocks the artery like a pipe: it builds up within the artery wall as a plaque.
Confusing coronary arteries with other blood vessels in the body.
Listing risk factors without explaining the mechanism linking them to CHD.
Saying CHD is only caused by diet: genetic predisposition is also a risk factor.