Section 1 of 9What is health?
Health is a state of complete physical and mental wellbeing, not just the absence of disease.
Section 2 of 9How diseases interact
Diseases rarely occur in isolation. One illness can make another more likely, and AQA expects you to give examples:
- If the immune system is weakened, for example by HIV infection, the body cannot defend itself properly and is more likely to suffer other infections,
- such as tuberculosis.
- Some viruses live inside body cells and can trigger the cells to divide out of control.
- Infection with human papillomavirus (HPV) can lead to cervical cancer.
This is why public health programmes try to deal with several problems together: vaccinating against HPV, for example, helps to prevent a cancer.
Section 3 of 9Diet, malnutrition and obesity
A balanced diet supplies the right amounts of carbohydrates, lipids, proteins, vitamins, minerals, fibre and water. Malnutrition means a diet that lacks, or has too much of, one or more of these nutrients.
BMI is calculated as mass in kg divided by height in metres squared.
- so blood glucose stays too high; it is controlled by a carbohydrate-controlled diet and exercise.
Section 4 of 9Stress and life situation
Long-term stress can raise blood pressure and weaken the immune system, and it is linked to mental illness.
Section 5 of 9Alcohol, smoking and other substances
Alcohol is processed by the liver, and heavy drinking can cause liver damage, brain damage and an unhealthy weight gain.
Section 6 of 9Putting it together: a worked scenario
Consider a man who is overweight, works long hours and eats mostly takeaway meals.
- and high blood pressure together with fatty deposits in his arteries increases the chance of coronary heart disease.
It also shows why doctors consider the whole person: treating only the physical symptoms may not improve a patient's health if diet, stress and life situation are not addressed. Public health campaigns therefore combine advice on diet and exercise with support for mental health and for people on low incomes.
Section 7 of 9Exam-style questions
Explain how infection with HIV can lead to a person developing tuberculosis. [3]3 marks
HIV damages the white blood cells of the immune system [1], so the person's immune system is weakened [1]. The body cannot fight off the bacteria that cause tuberculosis, so infection is more likely [1].
A man has a mass of 95 kg and a height of 1.75 m. Calculate his BMI and state whether it is above the obese threshold of 30. [3]3 marks
BMI = mass / height squared [1]. 1.75 squared = 3.0625; 95 / 3.0625 = 31.0 (31) [1]. This is above 30, so he is classed as obese [1].
Give two ways in which a person's life situation might affect their health. [2]2 marks
Any two: poverty leading to a poor diet [1]; poor housing or lack of clean water increasing infections [1]; stress from work or home affecting mental health [1]; exposure to harmful chemicals at work [1].
Section 8 of 9Key terms
| Term | Meaning |
|---|---|
| Health | A state of physical and mental wellbeing. |
| Malnutrition | A diet that lacks, or contains too much of, one or more nutrients. |
| Obesity | A condition of excess body fat, usually a BMI over 30. |
| Body mass index (BMI) | Mass in kilograms divided by height in metres squared. |
| Carcinogen | A substance or radiation that can cause cancer. |
| Type 2 diabetes | A disease where body cells no longer respond properly to insulin. |
| Deficiency disease | An illness caused by too little of a nutrient in the diet. |