The saying in Traditional Chinese Medicine that "Danggui transforms head stasis, Sanqi transforms heart stasis, Chaihu transforms liver stasis, and Duzhong transforms kidney stasis" essentially emphasizes syndrome-differentiated medication. Stasis symptoms differ depending on the body part affected. The medicinal properties and channel tropisms of these specific herbs precisely match the corresponding needs. Below is a simple analysis of the key principles.

First, let's discuss Danggui's role in transforming head stasis. When the channels in the head are obstructed by static blood, symptoms like headaches, dizziness, poor memory, a heavy feeling in the head, and a dull complexion can easily occur. Over time, this may lead to tinnitus and blurry vision. Danggui can both tonify blood and activate blood circulation. Its nature is mild and warm, capable of promoting the flow of qi and blood in the head while simultaneously replenishing qi and blood, thereby precisely alleviating the discomfort caused by stasis in the head.

Next, let's look at Sanqi (Notoginseng) for resolving heart blood stasis. When there is blood stasis in the heart vessels, the most obvious symptoms are chest tightness, stabbing pain, a feeling of pressure like a heavy stone, palpitations, shortness of breath, breathlessness when climbing stairs, or even waking up at night feeling suffocated. Sanqi has a strong effect in dispersing blood stasis, relieving pain, promoting blood circulation, and unblocking the vessels. It can directly clear blockages in the heart vessels, alleviate chest tightness and stabbing pain, and restore normal blood and Qi circulation in the heart.

The key to Chaihu (Bupleurum) in resolving liver blood stasis lies in its ability to soothe the liver and regulate Qi. Prolonged liver Qi stagnation can lead to blood stasis, resulting in symptoms such as distending pain in both flanks, irritability, dry eyes, and in women, breast distension and pain, as well as irregular menstruation. Chaihu can regulate and relieve stagnated liver Qi, promoting smooth Qi movement. Since the root cause of liver stasis is "Qi blockage," once Qi circulation is restored, the blood stasis naturally resolves.

Finally, Duzhong (Eucommia bark) for resolving kidney blood stasis. Blood stasis in the kidney area can lead to soreness and weakness in the lower back and knees, cold and weak knees, discomfort from prolonged standing or sitting, and possibly difficulty urinating. Duzhong can tonify the liver and kidneys, strengthen the bones and tendons, while also unblocking the meridians and promoting blood circulation. It not only enhances the ability of the liver and kidneys to propel blood and Qi but also resolves blood stasis in the kidney area, improving discomfort in the lower back and legs as well as urinary issues.

The core principle of using these four medicinal herbs to target and resolve blood stasis lies in aligning them with the causes and symptoms of stasis in different areas, precisely matching their medicinal properties and meridian tropisms. Only in this way can they efficiently resolve blood stasis issues in the corresponding areas.