Four stages

The Four Stages or Four Levels are from the Traditional Chinese medicine book Discussion of Warm Diseases by Ye Tianshi,^[1][2] who lived from 1667-1746.

The stages, in order, range from surface (or "light") sickness to internal (or "deep") death.

Wei level

• This level is treated by releasing the exterior (diaphoresis)
  • Wind-heat
  • Summer-heat
  • Damp-heat
  • Dry-heat

Qi level

• The Qi is treated by dispelling heat and promoting body fluids
  • Lung heat (heat in chest and diaphragm)
  • Stomach heat
  • Intestines dry-heat
  • Gall-bladder heat (heat in the lesser yang)
  • Stomach and Spleen damp heat

Ying level

• Ying (Nutritive qi) is treated by cooling fire and tonifing the yin
  • Heat in Nutritive qi portion
  • Heat in Pericardium

Blood level

• The Blood level treated by tonifing the yin and qi and stopping bleeding.
  • Heat Victorious moves blood
  • Heat victorious stirs wind
  • Empty wind agitates in the interior
  • Collapse of yin
  • Collapse of yang
  • Separation of yin and yang (Death)

References

• Maciocia, Giovanni. The Foundations of Chinese Medicine: A Comprehensive Text. ISBN 978-0-443-07489-9. 
• Maciocia, Giovanni (1994). The Practice of Chinese Medicine. ISBN 978-0-443-04305-5. 
• Tyme, L. Ac. Student Manual on the Fundamentals of Traditional Oriental Medicine (2nd ed.).