Explain how smoking cigarettes increases the risk of cardiovascular disease.

Edexcel GCSE Biology (1BI0) — 5.3 Non-communicable diseases · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Cardiovascular disease is one of the leading causes of death in the United Kingdom. Smoking is identified as a major lifestyle risk factor for developing this group of diseases.

Model answer (4 marks)

Carbon monoxide in cigarette smoke binds tightly to haemoglobin, reducing the oxygen‑carrying capacity of red blood cells.
This causes a drop in oxygen delivery to tissues, signalling the heart to beat faster.
The increased heart rate raises blood pressure, which damages the inner lining of arteries.
Damaged artery walls favour the deposition of atheromas (fatty plaques), narrowing the vessels and raising the risk of heart attack or stroke.

Examiner tips

Use the exact terms: carbon monoxide, haemoglobin, oxygen delivery, heart rate, blood pressure, artery walls, atheromas, heart attack or stroke.
Show the causal chain – each point must link to the next.
Keep it concise – 4–5 short sentences is enough for full marks.

Common mistakes

Failing to mention carbon monoxide or haemoglobin; students often write ‘tobacco smoke’ only.
Mixing up the order of events – e.g., stating atheroma formation before blood pressure rise.
Using vague language such as ‘bad effects’ instead of specific terms like ‘damaged artery walls’.

Mark scheme (4 marks)

Carbon monoxide (from cigarette smoke) binds to haemoglobin / reduces the ability of red blood cells to carry oxygen
The reduced oxygen delivery causes the heart rate to increase
Increased heart rate raises blood pressure, which damages artery walls
Damaged artery walls lead to the build-up of atheromas / fatty deposits, narrowing arteries and increasing the risk of heart attack or stroke

Key terms in this question

cardiovascular disease