Health (heart disease, high blood pressure, effects of cholesterol, stroke).

The idea

This statement links cardiovascular structure and function to health. Heart disease includes conditions such as coronary heart disease, where fatty plaques narrow the coronary arteries and reduce oxygen delivery to cardiac muscle. High blood pressure, or hypertension, means the force of blood against artery walls is persistently raised, increasing strain on the heart and arteries. Cholesterol is a lipid carried in the blood; low-density lipoprotein cholesterol contributes to plaque formation, while high-density lipoprotein cholesterol helps remove it. A stroke happens when blood supply to part of the brain is interrupted, often by a clot or a burst vessel. These conditions interact: raised cholesterol can worsen plaque build-up, which can raise blood pressure and increase heart disease and stroke risk.

What earns the marks

• Heart disease: coronary arteries narrowed by fatty plaque, reducing oxygen supply to cardiac muscle and causing angina or myocardial infarction.
• High blood pressure: persistently raised pressure in arteries increases cardiac workload and damages artery walls.
• Cholesterol: low-density lipoprotein cholesterol contributes to plaque formation; high-density lipoprotein cholesterol helps remove cholesterol from arteries.
• Stroke: interrupted blood supply to the brain, often from a clot or burst vessel, causing brain cell damage.
• Interactions: raised cholesterol can worsen plaque build-up, which can raise blood pressure and increase heart disease and stroke risk.

Common mistakes and how to put them right

• Misunderstanding: all cholesterol is harmful.

  Put it right: Cholesterol is needed for cell membranes and hormone production; the balance of low-density and high-density lipoprotein matters for cardiovascular health.

• Misunderstanding: high blood pressure only affects the heart.

  Put it right: It also damages arteries, the brain and kidneys, and raises stroke risk.

• Misunderstanding: a stroke is the same as a heart attack.

  Put it right: A heart attack affects cardiac muscle when coronary blood flow is blocked; a stroke affects the brain when cerebral blood flow is interrupted.

• Misunderstanding: heart disease is only caused by genetics.

  Put it right: Lifestyle factors such as diet, inactivity and smoking interact with genetics to influence risk.

Exam tips

• Read the question carefully to identify whether it asks about a cause, a mechanism or a health consequence.
• Link each condition to its effect on blood flow or oxygen delivery, not just its name.
• Eliminate options that confuse the heart and the brain, or that treat all cholesterol as harmful.