2.2.5: Health issues
Not started yet — this one needs some love.
Health: state of physical AND mental well-being.
Communicable diseases: caused by pathogens; can spread between people.
Non-communicable diseases: not caused by pathogens; cannot spread (e.g. cancer, CHD, Type 2 diabetes).
Disease interactions:
Defective immune system → more susceptible to infectious diseases.
Viruses inside cells can trigger cancers (e.g. HPV and cervical cancer).
Immune reactions to pathogens can trigger allergies (skin rashes, asthma).
Severe physical ill health can lead to depression and other mental illness.
Other factors: diet, stress, life situations can affect physical and mental health.
Common exam mistakes
Correlation ≠ causation: a statistical link between a risk factor and a disease does NOT prove one causes the other. A causal mechanism must be established separately.
Non-communicable diseases cannot be 'caught' or spread — you cannot catch cancer or heart disease from another person.
Must distinguish communicable (pathogen-caused, infectious) from non-communicable (lifestyle/genetic, non-infectious).