Silver Ear Fungus (Tremella fuciformis), also known as snow fungus or white jelly mushroom, has a long history of use in Traditional Chinese Medicine (TCM). It is especially valued for its purported ability to nourish the "yin" of the lungs and support the health of mucus membranes throughout the respiratory and gastrointestinal tracts. In TCM theory, it is often prescribed for dry coughs, dry throat, and overall dryness of the lungs, which are interpreted as signs of insufficient fluid or yin in the body.

The traditional rationale is based on observations that Silver Ear Fungus is moist and gelatinous, which is thought to help "moisten" the body’s tissues, particularly the mucus membranes. Silver Ear Fungus is commonly used in soups and desserts as both food and medicine for people suffering from dry conditions.

Scientific studies on Silver Ear Fungus have mainly focused on its polysaccharides, which have demonstrated immunomodulatory and skin-hydrating effects in vitro and in animal studies. However, direct clinical evidence supporting its efficacy for mucus membrane health in humans is lacking. Thus, while there is a plausible mechanism (hydration and immune effects), the use for supporting mucus membranes is supported primarily by traditional usage and not by robust clinical trials.