What is health, and how do lifestyle and non-communicable diseases such as cancer affect the body?
The definition of health, the difference between communicable and non-communicable disease, risk factors for non-communicable diseases, the effect of lifestyle, the development of cancer, and the interaction of different diseases.
A focused answer to AQA GCSE Biology 4.2.2, covering the definition of health, communicable and non-communicable disease, risk factors and lifestyle, the development of cancer, and how diseases interact.
Reviewed by: AI editorial process; not yet individually human-reviewed
Have a quick question? Jump to the Q&A page
Jump to a section
What this dot point is asking
AQA wants you to define health, distinguish communicable from non-communicable disease, describe risk factors and the effect of lifestyle, explain how cancer develops, and explain how different types of disease can interact.
What is health?
Diseases are a major cause of ill health, but diet, stress and a person's life situation also affect both physical and mental health, and these factors can influence one another.
Communicable and non-communicable disease
- Communicable diseases are caused by pathogens (bacteria, viruses, fungi, protists) and can be passed from one person to another, for example measles or flu.
- Non-communicable diseases cannot be transmitted from person to person; they tend to last a long time and often get worse slowly. Examples include cardiovascular disease, type 2 diabetes and most cancers.
The cost of non-communicable diseases is huge, both to individuals (poorer quality of life, early death) and to society and the economy (treatment costs, lost working days).
The development of cancer
- Benign tumours grow in one place, usually within a membrane, and do not spread to other parts of the body, so they are usually less dangerous.
- Malignant tumours are cancers: their cells invade neighbouring tissues, and cells can break off and spread in the blood to other parts of the body, forming secondary tumours.
Both lifestyle risk factors (such as smoking and UV exposure) and genetic risk factors can contribute to cancer.
How diseases interact
Different types of disease can affect one another. For example, defects in the immune system mean a person suffers more from communicable diseases; some viruses living in cells can trigger cancers; immune reactions caused by a pathogen can trigger allergies such as skin rashes and asthma; and severe physical ill health can lead to depression and other mental illness.
Try this
Q1. Give one example of a non-communicable disease and one risk factor for it. [2 marks]
- Cue. For example, cardiovascular disease, with smoking or a poor diet as a risk factor.
Q2. State the difference between a benign and a malignant tumour. [2 marks]
- Cue. Benign stays in one place; malignant spreads to other parts of the body.
Exam-style practice questions
Practice questions written in the style of AQA exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
AQA 20204 marksA study found that the number of cases of a lung disease increased as the number of cigarettes smoked per day increased. Explain what this shows about smoking as a risk factor, and why this data alone does not prove that smoking causes the disease.Show worked answer →
A 4-mark question rewards interpreting data and the correlation-versus-causation idea.
The data shows a correlation: as the number of cigarettes increases, the number of cases of the disease increases, so smoking is a risk factor for the disease. The more cigarettes smoked, the higher the risk, which is a dose-response relationship that strengthens the link.
However, a correlation alone does not prove cause, because another factor could be responsible, for example smokers may also have other lifestyle differences. To establish that smoking causes the disease, scientists also need a biological mechanism (how chemicals in smoke damage the lungs) and further studies.
Markers reward identifying the positive correlation (risk factor), the dose-response, and the point that correlation does not prove causation without a mechanism.
AQA 20214 marksDescribe the difference between a benign and a malignant tumour, and explain how malignant tumours can lead to secondary tumours in other parts of the body.Show worked answer →
A 4-mark question rewards the difference plus the spread mechanism.
A benign tumour grows in one place, usually contained within a membrane, and does not invade other tissues, so it is not normally dangerous unless it presses on an organ. A malignant tumour is a cancer: the cells divide uncontrollably and invade neighbouring tissues.
Cells can break off a malignant tumour and travel in the blood (or lymph) to other parts of the body, where they invade and grow to form new tumours called secondary tumours. This spread is what makes malignant tumours dangerous.
Markers reward benign staying in one place, malignant invading and spreading, and cells travelling in the blood to form secondary tumours.
Related dot points
- The levels of organisation from cells to tissues, organs and organ systems, the meaning of each level, and how the digestive system is an example of an organ system, including the action of enzymes.
A focused answer to AQA GCSE Biology 4.2.1, covering the levels of organisation from cells to tissues, organs and organ systems, with the digestive system as the worked example.
- The structure of the heart and the double circulatory system, the roles of the arteries, veins and capillaries, how the heart rate is controlled, and the structure and function of the lungs in gas exchange.
A focused answer to AQA GCSE Biology 4.2.2, covering the structure of the heart, the double circulatory system, the three types of blood vessel, control of heart rate, and the structure of the lungs for gas exchange.
- Blood as a tissue made of plasma, red blood cells, white blood cells and platelets, the function of each component, and how red blood cells are adapted to carry oxygen.
A focused answer to AQA GCSE Biology 4.2.2, covering blood as a tissue, the functions of plasma, red blood cells, white blood cells and platelets, and the adaptations of red blood cells for carrying oxygen.
- Pathogens as disease-causing microorganisms, the four types (bacteria, viruses, fungi and protists), how each makes us ill, and named examples of communicable diseases caused by each type.
A focused answer to AQA GCSE Biology 4.3.1, covering pathogens, the four pathogen types (bacteria, viruses, fungi and protists), how they make us ill, and named examples of the diseases they cause.
- Chromosomes, the cell cycle and mitosis, the role of mitosis in growth and repair, stem cells in embryos, adult tissue and plant meristems, and the uses and issues of therapeutic cloning and stem cell treatments.
A focused answer to AQA GCSE Biology 4.1.2, covering chromosomes, the cell cycle and mitosis, the role of mitosis in growth and repair, and the sources and uses of stem cells.
Sources & how we know this
- AQA GCSE Biology (8461) specification — AQA (2016)