the theory of the 4 humours

• Theory of the four humors


  One of the most important ancient medical ideas, incredibly important in the medieval period and even after
• Theory of the four humors


  • Based upon the ideas of Greek philosophers like Aristotle, particularly used by Greek doctor Hippocrates
  • Used by Hippocrates to help diagnose illnesses and suggest treatments
  • Logical step towards trying to diagnose people in a scientific way, although not necessarily right
• Four humors


  • Blood
  • Phlegm
  • Black bile
  • Yellow bile
• Balance of humors


  • If all humors in the body are balanced, a person is well
  • If there is too much or too little of a particular humor, the person becomes unwell
• Imbalance of humors

  Cause of illness
• Certain illnesses

  More common at different times of the year
• Colds and phlegm are more common in wet and cold seasons (e.g. winter, spring) because people spend more time indoors and are more likely to pick up bugs, not because of humors
• Symptoms and treatments based on four humors


  • Cold: Too much phlegm, treatment to extract phlegm
  • Rash and fever: Too much blood, treatment to bleed patient
  • Constipation: Too little black bile, treatment to eat laxative foods
• The four humors theory represented progress in ancient Greek times as a scientific and rational explanation for illness, even if incorrect
• In medieval times, the four humors theory represented continuity as an old idea that survived for a very long time, with treatments like bleeding lasting into the 19th century
• The four humors theory was eventually challenged in the Renaissance, but some beliefs and treatments based on it persisted until Pasteur's germ theory