In the process of using TCM medications, accurate syndrome differentiation and proper compatibility are very crucial. Some herbs, although highly effective, may worsen existing conditions if used improperly. Today, let's discuss three important cases and how to use them correctly.

First, use Astragalus membranaceus with caution in cases of kidney deficiency. Although Astragalus is a good herb for tonifying qi, it primarily works by enhancing the qi of the spleen and lungs. If used alone for people with insufficient kidney qi, it may excessively raise qi activity, thus exhausting the fundamental qi of the kidneys. The kidneys govern containment, and overusing ascending herbs may lead to qi not returning to its origin, resulting in symptoms like lower back and leg weakness and increased nighttime urination. Therefore, if someone with kidney deficiency needs to tonify qi, they often need to combine it with herbs like Euryale ferox and Schisandra chinensis, which consolidate and astringe the kidneys, ensuring that tonification is balanced with containment to prevent the exhaustion of essence and qi.

Secondly, caution should be exercised when using aconite for weak heart qi. Aconite is extremely pungent and hot, capable of reviving yang and warming the heart, but if the heart qi is already weak, relying solely on aconite's strong stimulation is like forcing a tired horse to run—though it may run temporarily, it will eventually exhaust itself. Such individuals may experience worsened palpitations, restlessness, insomnia, and excessive sweating, known as the "floating yang" phenomenon. The correct approach is to combine warming yang with herbs that astringent and calm the spirit, such as oyster shell and magnetite. These herbs can both support yang and subdue it, allowing the yang to return to its proper place.

Thirdly, caution should be exercised when using bupleurum for liver blood deficiency. Bupleurum can soothe the liver and lift yang, but its nature is inclined to rise and disperse. The liver is yin in nature but uses yang, so if the liver blood is already deficient, excessive use of ascending and dispersing herbs may further deplete the yin and blood, leading to dizziness, numbness in limbs, and spasms of tendons and muscles, known as "blood failing to nourish the sinews." In such cases, herbs that nourish blood and soften the liver, such as white peony root and prepared rehmannia, should be combined. This ensures that the liver is soothed without neglecting to nourish it, and qi is regulated without harming the yin and blood.

A middle-aged woman once visited the outpatient clinic complaining of fatigue and weakness. She had been self-administering long-term doses of astragalus steeped in water, which instead led to worsening lower back pain and increased nighttime urination. Her pulse was deep and thin, and her tongue was pale with a white coating, indicating typical kidney qi deficiency. I advised her to stop using single-herb astragalus and switch to modified Jinkui Shenqi Pill. Two weeks later, she reported significant improvement in her lower back pain and nighttime urination, and her strength gradually returned.

In summary, the use of traditional Chinese medicine lies in balanced compatibility and individualized treatment. It is recommended to use herbs based on syndrome differentiation under the guidance of a professional physician to maximize efficacy while avoiding deviations.