Health Is Physical and Mental Wellbeing, Not Just the Absence of Disease
Health
The state of physical and mental wellbeing, not simply the absence of disease.
- Health is the state of physical and mental wellbeing, not simply being free of disease.
- Good physical health means the body and its organs are working properly.
- Good mental health means a person can cope with the normal demands of everyday life.
- Health is affected by diet, stress, life situation and whether a person can get medical care.
You can carry no infection and still be in poor health because of a poor diet, high stress or a difficult life situation.
Communicable Diseases Spread Between Organisms
Communicable disease
A disease that can spread from one organism to another because it is caused by a pathogen, such as a bacterium, virus, fungus or protist.
- A disease is a condition that stops part of the body working normally and causes symptoms.
- A communicable disease can be passed from one organism to another because it is caused by a pathogen.
- Examples include measles, influenza and chickenpox.
Non-Communicable Diseases Cannot Be Caught
Non-communicable disease
A disease that cannot be passed from one person to another; it is not caused by a pathogen and often develops slowly, such as coronary heart disease, type 2 diabetes and most cancers.
- A non-communicable disease cannot be spread and is not caused by a pathogen.
- Examples include coronary heart disease, type 2 diabetes and most cancers.
- Both communicable and non-communicable diseases are major causes of ill health.
Do not assume every illness can be caught; non-communicable diseases such as heart disease cannot be passed from person to person.
Different Diseases Can Interact
- A defect in the immune system leaves a person more likely to catch infectious diseases; for example, HIV lowers the number of lymphocytes, so infections like pneumonia take hold.
- Some viruses living in cells can trigger cancers, such as HPV leading to cervical cancer.
- An immune reaction first caused by a pathogen can trigger allergies such as skin rashes and asthma.
- Severe physical ill health can lead to depression and other mental illness.
Because one disease can make another more likely, a doctor considers a person's whole health rather than one illness on its own.
Studying How Common Diseases Are
- Scientists study the incidence of a disease, which is how many people in a population develop it.
- They study a sample of the population rather than every individual, because studying everyone would be impossible; a sample must be large enough to be representative.
- The data is shown in frequency tables, bar charts and histograms, and a scatter diagram is used to look for a correlation between two variables.
- Give a definition of health.
- What is the difference between a communicable and a non-communicable disease? Give one example of each.
- Explain why a defect in the immune system can lead to more infectious diseases.
- Give one other way that two diseases can interact.
- Why do scientists use a sample of a population when studying disease?
