The Four Humours

• The theory of the four humors was based upon the ideas of Greek philosophers like Aristotle and used by Greek doctor Hippocrates to diagnose illnesses and suggest treatments
• The theory of the four humors

  • The body was composed of four liquids or humors linked to the four elements and the seasons: blood, phlegm, black bile, and yellow bile
• Fluids representing the 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
• Seasons and illnesses

  Certain illnesses seem to be more common at different times of the year, possibly related to the balance of humors
• The theory of the four humors attempted to explain how illness was caused without relying on supernatural ideas like evil spirits and God
• Cold symptoms

  • Shivers, lots of phlegm and snot
• Cold symptoms

  Ancient Greeks would attribute it to too much phlegm and suggest treatments to balance the humors, such as extracting phlegm or breathing in vapors
• Ancient Greek medical beliefs

  • Too much phlegm causing lots of phlegm and snot, treatment involves extracting phlegm to balance humors, methods like blowing nose or inhaling vapors
  • Too much blood causing rash and fever, treatment involves bleeding the patient to restore balance of humors
  • Too little black bile causing constipation, treatment involves eating laxative foods to induce deliberate diarrhea
• Imbalance in humors

  Causes illness
• The theory of the four humors includes blood, black bile, yellow bile, and phlegm
• Illness is believed to result from imbalances in the humors
• The theory of the four humors was a rational explanation of illness, although incorrect
• Treatments based on the four humors treated symptoms, not the cause of the disease
• Preventions based on the four humors were either common sense or potentially harmful, such as bleeding
• The theory of the four humors remained one of the most widespread theories of the cause of disease for centuries
• Progress of the idea of the four humors

  Represented progress in ancient Greek times, continuity in medieval times, and regress in the Renaissance and beyond