Health and disease (AQA GCSE Biology Combined Science): Revision Notes
Health and disease
What is health?
Health is not just about being free from disease. Health means having complete physical and mental wellbeing.
Health has three main parts:
- Physical wellbeing - Your body works properly. You eat well, sleep well, and stay free from disease
- Mental wellbeing - How you feel about yourself emotionally
- Social wellbeing - How well you get along with other people
All three parts work together to make you healthy. If one part suffers, it can affect the others too. This interconnected nature of health means that maintaining balance across all areas is essential for overall wellbeing.
Types of disease
There are two main types of disease:
Non-communicable diseases
These diseases cannot be passed from one person to another.
Key features:
- Number of cases changes slowly over time
- Cases are often widespread across the population
- Examples: heart disease, cancer, diabetes
Non-communicable diseases are often linked to lifestyle factors and genetic predisposition, making prevention through healthy living particularly important.
Communicable diseases
These diseases can be passed from one person to another.
Key features:
- Number of cases can change rapidly over time
- Cases are often found in specific areas (localised)
- Examples: colds, flu, measles, food poisoning
The rapid spread of communicable diseases makes early detection and prevention measures crucial for public health.
Factors affecting health
Diseases are not the only things that affect your health. Other factors include:
- Diet - eating too much or too little
- Stress - from work, school, or personal problems
- Life situations - poverty, relationships, family problems
These factors often work together and can create a cycle where one problem leads to another. For example, stress can lead to poor eating habits, which can then affect physical health and increase stress levels further.
How diseases interact with each other
Sometimes having one health problem can make you more likely to get another problem. This interconnection between different health conditions is a crucial concept in understanding overall health and disease prevention.
| Disease or problem | Additional problem it can cause |
|---|---|
| Weak immune system | Makes you more prone to infectious diseases |
| Immune reaction caused by a pathogen | Can trigger allergies (like skin rashes or asthma) |
| Severe physical ill-health | Can lead to mental illness such as depression |
| Viruses in cells | Can be a trigger for cancer |
Worked example: H. pylori bacteria
Worked Example: H. pylori and Stomach Ulcers
H. pylori is a bacterium that lives in the stomach lining. Here's what you need to know:
Background:
- Most people catch it during childhood, probably from family members
- About 20% of people in the UK have H. pylori
- It causes stomach ulcers in about 15% of infected people
- Taking aspirin for a long time also causes stomach ulcers
Treatment: A course of antibiotics kills H. pylori and heals most ulcers in 1-2 months. If ulcers are caused by aspirin, doctors can prescribe other painkillers.
Classification Question: Is it communicable? H. pylori can be caught from other people, so it might be a communicable disease. However, most infected people don't develop ulcers, and some people develop ulcers from taking aspirin. More research is needed to be completely sure.
Key Points to Remember:
- Health means complete physical and mental wellbeing - not just being free from disease
- Non-communicable diseases cannot spread between people (like cancer, diabetes)
- Communicable diseases can spread between people (like colds, flu)
- Different health factors interact - having one problem can lead to others
- H. pylori bacteria cause stomach ulcers and can be treated with antibiotics