Expel Water Retention came out of “Treatise on Febrile Diseases” by Zhang Zhongjing in the late Eastern Han Dynasty. It has the effect of inducing urination to remove Water and Damp Retention, warming Yang and Qi to transport Water and Dampness. It is indicated for Water Retention Syndrome. The Water Retention Syndromes of Bladder referring to “Treatise on Febrile Disease”, is a series of symptoms caused by unfavourable transport of Water by the Bladder. This is resulting in Stagnation of Water in the body, such as oedema caused by water overflowing to the skin, vomiting caused by Stagnation of Water in the Stomach; watery diarrhoea caused by Water Stagnation in the Large Intestine; vertigo caused by Water overflowing and blocking head; cough and shortness of breath by Water Stagnating in the Lungs; palpitation by Water in Lung overflowing to the Heart. Clinically used to help acute and chronic nephritis, oedema, ascites due to liver cirrhosis, cardiogenic oedema, acute enteritis, urinary retention, hydrocephalus, which are Water Retention Syndromes in Chinese medicine.

Modern researches show that this Expel Water Retention can regulate the body’s water-salt balance and diuresis. It can inhibit the high expression of ETAR protein and mRNA in kidney tissue of patients with ADR nephropathy, which may be one of its mechanisms of reducing proteinuria in patients with ADR nephropathy.