Non-communicable disease

Non-communicable diseases (NCDs) are not caused by pathogens and cannot be passed from one person to another. They include cardiovascular disease, type 2 diabetes, many cancers, and chronic respiratory disease.

Risk factors

A risk factor is anything that increases the chance of developing a disease. Risk factors do not guarantee illness — they raise probability.

Risk factor	Diseases linked
Smoking	Lung cancer, COPD, cardiovascular disease
Poor diet (high fat, salt, sugar)	Cardiovascular disease, type 2 diabetes, obesity
Lack of exercise	Cardiovascular disease, type 2 diabetes, obesity
Alcohol	Liver disease (cirrhosis), some cancers
Obesity (BMI > 30)	Type 2 diabetes, cardiovascular disease, joint problems
UV / sun exposure	Skin cancer
Ionising radiation	Leukaemia, other cancers

Causal vs correlated

A correlation simply means two variables move together. A causal link means one actually causes the other. Establishing causation requires:

• A plausible biological mechanism
• Evidence from multiple studies, ideally randomised
• A dose-response relationship (more exposure to more disease)

Cardiovascular disease (CVD)

Build-up of fatty plaques (atherosclerosis) in coronary arteries reduces blood flow to the heart muscle.

Treatments:

• Lifestyle change — stop smoking, exercise, low-fat diet, lose weight.
• Statins — drugs that lower blood cholesterol, slowing plaque build-up.
• Stents — small mesh tubes that hold narrowed arteries open.
• Coronary bypass surgery — replaces blocked arteries with vessels from elsewhere.
• Heart transplant — last resort.

Type 2 diabetes

Cells become resistant to insulin so blood glucose stays high. Strongly linked to obesity.

Treatments:

• Diet (low-carb, controlled portions)
• Exercise (improves insulin sensitivity)
• Medication (metformin)
• Insulin injections in advanced cases

WJEC exam tip

When asked to suggest treatments, always include a lifestyle change option as well as a medical one. Examiners reward candidates who recognise that prevention and early intervention are usually first-line care.