Helicteres isora, commonly known as the Indian screw tree, has a history of use in traditional medicine systems such as Ayurveda and folk medicine in India and Southeast Asia. Traditionally, it has been used for a variety of ailments, including coughs, asthma, and respiratory congestion. The roots, bark, and fruits of the plant are often prepared as decoctions or powders for these purposes. The rationale for its use in congestion is primarily based on its reported expectorant and anti-inflammatory properties in traditional practices.

However, scientific studies specifically evaluating Helicteres isora for the treatment of lung congestion are sparse. While some in vitro and animal studies have identified the presence of bioactive compounds such as flavonoids, saponins, and tannins with potential anti-inflammatory and antioxidant activities, direct evidence of efficacy against airway congestion in humans is lacking. There are a few studies noting its use in cough and asthma models in animals, but these are preliminary and do not provide strong clinical evidence.

In summary, the use of Helicteres isora for lung congestion is primarily justified by traditional knowledge, with minimal scientific validation as of now. Further research, particularly well-designed clinical trials, would be necessary to establish its safety and efficacy for this indication.