Risk factors for non-communicable diseases
Laura Armstrong & Joe Wolfensohn
Teachers
Recall Questions
This topic requires prior knowledge of cardiovascular disease and the heart.
What is the function of the coronary arteries?
To supply oxygenated blood to the heart muscle.
What is cholesterol, and how can high levels affect the arteries?
Cholesterol is a fatty substance in the blood; high levels can lead to the build-up of fatty deposits (plaques) in arteries, narrowing them.
What lifestyle factors increase the risk of coronary heart disease?
Smoking, high-fat diet, lack of exercise, and obesity.
Topic Explainer Video
Check out this @JoeDoesBiology video that explains risk factors for non-communicable diseases, then read the study notes. Once you’ve gone through them, don’t forget to try the practice questions!
Health & Disease Overview
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Health = state of complete physical and mental wellbeing.
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Disease can be communicable (infectious) or non-communicable (not infectious).
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Poor health increases the risk of developing other conditions (e.g. infections and mental illness).
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A non-communicable disease is one that cannot be transferred between organisms, it is not contagious or infectious.
What Is a Risk Factor?
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A risk factor is something that increases the probability of developing a disease.
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Not all people exposed to risk factors will develop the disease - they just increase the likelihood.
Types of Risk Factors
|
Risk Factor |
Linked Non-Communicable Disease(s) |
|
Smoking |
Lung cancer, cardiovascular disease |
|
Obesity |
Type 2 diabetes, heart disease |
|
Alcohol |
Liver disease, brain damage, birth defects |
|
Poor diet & lack of exercise |
Cardiovascular disease, type 2 diabetes |
|
Genetics |
Certain cancers, inherited disorders |
|
Exposure to carcinogens |
Lung cancer |
|
Smoking or alcohol (during pregnancy) |
Developmental problems in fetus |
Pregnancy & Risk Factors
Risk factors during pregnancy can significantly impact embryonic and fetal development.
These impacts occur because harmful substances cross the placenta as well as less oxygen being delivered to the foetus.
Smoking During Pregnancy
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Cigarette smoke contains carbon monoxide and nicotine.
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Carbon monoxide reduces the amount of oxygen delivered to the foetus.
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Nicotine narrows blood vessels in the mother and placenta, further restricting oxygen and nutrient flow.
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Consequences:
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Increased risk of premature birth or misscarriage
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Low birth weight, which is linked to higher infant mortality.
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Potential developmental delays and respiratory problems in early life.
Alcohol Use During Pregnancy
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Alcohol passes freely from the mother's blood into the fetal circulation.
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The foetus lacks the enzymes to break down alcohol, so it remains in the body longer and at higher concentration.
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Fetal Alcohol Syndrome (FAS) is a serious consequence of drinking during pregnancy.
FAS effects include:
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Brain damage and learning difficulties.
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Facial deformities.
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Growth restriction (below-average weight and height).
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Behavioural and emotional problems.
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Increased risk of premature birth or misscarriage
Interaction of Risk Factors
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Multiple risk factors can interact:
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e.g. poor diet + smoking + lack of exercise all increase the risk of heart disease more than each factor alone.
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Socioeconomic status, access to healthcare, and environment also influence disease risk.
Key Terms
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Risk factor – A variable linked to an increased chance of disease.
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Non-communicable disease – A disease that cannot be passed between people.
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Carcinogen – A substance capable of causing cancer.
No answer provided.
Exam Tip
- Use the phrase “increases the likelihood” in risk factor questions.
No answer provided.
Practice Question
Explain why smoking is considered a risk factor during pregnancy. (4 marks)
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Cigarette smoke contains harmful substances such as nicotine and carbon monoxide.
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Carbon monoxide reduces the amount of oxygen carried in the mother's blood by binding to haemoglobin.
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This leads to less oxygen being delivered to the developing foetus, which is essential for healthy growth.
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As a result, smoking increases the risk of low birth weight, premature birth, and developmental problems in the baby.
More Practice
Try to answer these practice questions from the TikTok videos on your own, then watch the videos to see how well you did!