Practitioners of Chinese Medicine and Qigong observed this long ago and explained it through their theory of the meridians and elements.
At the root of it, anything that has to do with the immune system will involve the "wei qi" - a poetic way of describing the body's capacity to defend itself.
The SOURCE of this defensive energy is said to come from three places, one is the energy from the food we digest, another is from our breathing, and the last is from our reserves (including ideas of genetics, how much rest we've been getting, stress, and more).
If this energy-drain goes on for too long, it is believed, the process begins drawing on one's reserves - leading to lasting after-effects because of deficiency of the "vital substances" of the body. These "vital substances" refer to the capacity of our systems to repair themselves, as well as carry out their everyday functions.
Symptoms like weakness, lingering cough, shortness of breath, anxiety, heart palpitations, fatigue, brain-fog, and digestive problems following a long-term illness are all taught to be caused by this depletion of the body's energetic reserves.
Fortunately, Medical Qigong exercises aim to address this by working on specific meridians and organs that govern the replenishment of these energetic reserves.
In particular, Qigong therapy will focus tonifying the Lung, Spleen/Pancreas, and Kidney organ/meridians to bolster these three components of the defensive Qi - the Breath, Nourishment, and Reserves. With a properly designed practice, some will see a reduction in their lingering symptoms within days of beginning the practice, or even after the first session!
My latest mini-course online contains exercises for bolstering these specific organs and meridians in the body as part of Seasonal Qigong Therapy for the Autumn. Check it out!
[medical qigong is not a substitute for medical care and is traditionally combined with herbalism, acupuncture, and nutrition for best effect]
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