When the Fire of Digestion Goes Out
In traditional Chinese medicine, the spleen and kidneys are closely linked. The spleen is responsible for digestion (“postnatal qi”), and the kidneys for the innate constitution (“prenatal qi”). There is a classic pathological mechanism whereby a prolonged deficiency of the spleen’s yang inevitably leads to a deficiency of the kidney’s yang.
Spleen Yang: The Cooking Fire
Imagine the spleen as a cooking pot on a fire. The fire is the “yang” energy needed to digest food and convert it into energy and heat. If you constantly eat cold, raw foods (such as ice cream, crudites, cold drinks) or live in a cold environment, this fire has to work increasingly harder. Eventually, the fuel runs out: Spleen Yang Deficiency. Symptoms include cold hands, loose stools, fatigue after eating, and abdominal distention.
The Role of the Kidneys
The Kidneys are the source of all fire in the body (Kidney Yang or “Ming Men Fire”). When the Spleen Yang is weakened, the body cannot extract enough energy from food. To keep digestion running smoothly, the body calls upon its “reserves”: the Kidney Yang. The Kidneys begin to lend their precious fire to the Spleen to keep the pot warm.
The Exhaustion
This is an emergency measure that can’t last forever. Constantly “borrowing fire” will eventually exhaust the resource.
The result:
A combined Spleen and Kidney Yang Deficiency.
The Symptoms:
The symptoms worsen and descend to a deeper level. In addition to digestive complaints, chronic diarrhea in the early morning (“Cock’s crow diarrhea”), a deep cold in the lower back and knees, frequent urination at night, edema in the legs, and a profound, constitutional fatigue and apathy now also develop.
Conclusion
This pattern demonstrates why protecting your digestive system is so crucial for long-term health. By eating warm food and protecting your spleen, you indirectly conserve your kidney energy and thus your longevity and vitality.