Glehnia root (Glehnia littoralis, also known as "Bei Sha Shen" in traditional Chinese medicine) has a long history of use in East Asian herbal medicine, particularly for addressing respiratory conditions. In traditional Chinese medicine (TCM), it is considered to nourish the lungs, moisten dryness, and address symptoms such as dry cough, sore throat, and thirst—symptoms that can accompany pneumonia and other lung disorders. Glehnia root is commonly included in multi-herb formulations intended to treat lung yin deficiency and to relieve cough associated with heat or dryness in the lungs.

The scientific evidence supporting Glehnia root's effectiveness specifically for pneumonia is limited. Some pharmacological studies suggest that Glehnia root contains polysaccharides and other compounds with potential anti-inflammatory, antioxidant, and immunomodulatory effects, which may theoretically benefit respiratory health. However, robust clinical trials in humans, particularly for pneumonia, are lacking. Most evidence for its use in pneumonia is based on tradition and its inclusion in classical Chinese herbal formulas rather than direct modern research.

In summary, while Glehnia root is traditionally used to support lung health and may be included in herbal protocols for symptoms compatible with pneumonia, its use for this specific condition is justified primarily by historical practice rather than strong scientific validation.