Health, Lifestyle & Cancer

Health and disease

• Health is the state of physical and mental well-being
• Diseases, both communicable (infectious, spread by pathogens) and non-communicable (not spread between people), are major causes of ill health. Diet, stress and life situations also affect physical and mental health
• Different diseases interact:
  • Defects in the immune system make infectious diseases more likely
  • Viruses living in cells can trigger cancers (HPV and cervical cancer)
  • Immune reactions to a pathogen can trigger allergies such as skin rashes and asthma
  • Severe physical ill health can lead to depression and other mental illness
• Reading disease data: check whether a graph shows numbers or rates, identify the trend for each group separately, and quote figures with units. A scatter diagram shows a correlation between two variables; a correlation does not prove one causes the other
• Sampling: a sample must be large enough and representative of the whole population for conclusions to be valid