In Traditional Chinese Medicine (TCM), Hua Shi belongs to the 'Herbs that drain Dampness' category. These herbs are typically diuretics, meaning that they promotes the increased production of urine in order to remove Dampness that has accumulated in the body. According to TCM Dampness accumulates first in the lower limbs, causing edema and impaired movement. From there, if unchecked, it can move upward and impair digestion and eventually the respiratory system.
Furthermore Hua Shi is Cold in nature. This means that Hua Shi typically helps people who have too much 'Heat' in their body. Balance between Yin and Yang is a key health concept in TCM. Those who have too much Heat in their body are said to either have a Yang Excess (because Yang is Hot in nature) or a Yin deficiency (Yin is Cold in Nature). Depending on your condition Hua Shi can help restore a harmonious balance between Yin and Yang.
Hua Shi also tastes Sweet. The so-called 'Five Phases' theory in Chinese Medicine states that the taste of TCM ingredients is a key determinant of their action in the body. Sweet ingredients like Hua Shi tends to slow down acute reactions and detoxify the body. They also have a tonic effect because they replenish Qi and Blood.
The tastes of ingredients in TCM also determine what Organs and Meridians they target. As such Hua Shi is thought to target the Bladder and the Stomach. In TCM the impure water collected by the Kidneys that cannot be used by the body is sent to the Bladder for storage and excretion as urine. The Stomach on the other hand is responsible for receiving and ripening ingested food and fluids. It is also tasked with descending the digested elements downwards to the Small Intestine.