--- title: "Non-Communicable Disease and What Counts as a Risk Factor" description: "Non-communicable diseases are not passed from person to person. Risk factors are linked to a higher chance of disease, not a guarantee. Some contribute to causing disease; others are markers. Compare " canonical: https://lightmysky.com/learn/science/non-communicable-disease-and-what-counts-as-a-risk-factor-mt_IciZ1CJn6h source: https://lightmysky.com/learn/science/non-communicable-disease-and-what-counts-as-a-risk-factor-mt_IciZ1CJn6h.md retrieved: 2026-11-12 --- > **Agent view.** This is the Markdown twin of the page, for tools and assistants. > When to use this site, and the call that answers each job: https://lightmysky.com/agent-instructions.md > API description (OpenAPI 3.1): https://lightmysky.com/openapi.json · Authentication: https://lightmysky.com/auth.md > Pricing: https://lightmysky.com/pricing.md · Catalog: https://lightmysky.com/llms.txt · Full catalog: https://lightmysky.com/llms-full.txt > Every machine-readable file on this domain: https://lightmysky.com/.well-known/ai-catalog.json > Ask for Markdown with `Accept: text/markdown`, a `.md` address, or `?mode=agent`. # Non-Communicable Disease and What Counts as a Risk Factor Non-communicable diseases are not passed from person to person. Risk factors are linked to a higher chance of disease, not a guarantee. Some contribute to causing disease; others are markers. Compare correlation with evidence about causes and mechanisms, and distinguish benign from malignant tumours. Subject: Science · Area: The Human Body · Ages 15 to 16 Page: https://lightmysky.com/learn/science/non-communicable-disease-and-what-counts-as-a-risk-factor-mt_IciZ1CJn6h ## Ready when they can - Explain what a risk factor is and why it does not guarantee the disease - Give a case where a mechanism is known and a case where only a correlation has been shown - Describe how uncontrolled cell division becomes a tumour and distinguish benign from malignant ## Lesson: Risk factors are not guarantees Non-communicable diseases do not pass between people. Risk factors are features or exposures linked to higher disease risk, not certainty. Some help cause disease; others are markers. DNA carries genetic instructions; genes are sections of DNA. Inherited gene variants are gene differences passed from parents. Smoking, inherited variants and certain infections can raise cancer risk. Infections may spread between people; the resulting cancer is not caught from another person. You have met correlation before: two things are associated, but that alone does not establish cause. A survey linking a food with more disease shows an association; other factors could explain it. A mechanism explains how an effect happens. Scientists weigh several kinds of evidence. A plausible mechanism alone is not proof, and an unknown mechanism does not rule out a causal link. **Example.** Tobacco smoke chemicals can damage DNA. Changes disrupting cell-division controls can contribute to cancer. This is one biological pathway linking smoking to cancer. Smoking causes lung cancer and is a risk factor, but not every smoker develops it. Evidence beyond this pathway supports the causal conclusion. *(drawing: These changes can contribute to cancer. This pathway does not occur after every exposure or in every person.)* Cells normally have controls that limit division. If these break down, abnormal cells may keep multiplying and form a tumour. Benign tumours do not invade nearby tissue or spread elsewhere, though they can cause harm by pressing on organs. Malignant tumours are cancerous: they can invade nearby tissue and may spread to distant sites. They need not have spread already to be malignant. Some cancers, such as leukaemia, do not form solid tumours. Reducing a causal risk factor can lower disease risk without removing it. Stopping smoking lowers future lung cancer risk, but cannot promise that cancer will never occur. Changing an associated marker may not reduce disease if the marker is not a cause. Some risk factors, such as age or inherited variants, cannot be changed. Prevention decisions need evidence about likely benefits and harms. **Recap.** Risk factors indicate higher chance, not certainty. Correlation alone does not establish cause. Benign tumours do not invade or spread; malignant tumours can. *Lesson, questions and flashcards written for this dataset, with factual background from OpenStax.* ## Practice 8 questions on this page, each with its working shown. ## Needs first - [The Digestive System and Testing Food for Nutrients](https://lightmysky.com/learn/science/the-digestive-system-and-testing-food-for-nutrients-mt__mBJCQEqPS) - [Effects of Drugs & Alcohol](https://lightmysky.com/learn/science/effects-of-drugs-and-alcohol-mt_2R3xRpYhMa) - [Correlation vs Causation](https://lightmysky.com/learn/science/correlation-vs-causation-mt_X0Tr8IYaEd) ## Optional connections - [Diet Imbalance & Deficiency](https://lightmysky.com/learn/science/diet-imbalance-and-deficiency-mt_NZHFcEtTyI) ## Opens up - [Testing a New Drug: Controls, Placebo and the Blind Trial](https://lightmysky.com/learn/science/testing-a-new-drug-controls-placebo-and-the-blind-trial-mt_If6qHIrOxT)