Rehmannia glutinosa acts as a diuretic, clears heat and fire (removes heat and fire from the body), removes vexation, and produces fluids and quenches thirst (promotes the production of fluids to quench thirst). Rehmannia glutinosa, cold in nature, sweet in taste, belongs to the lung and stomach meridians; its effects are to remove vexation, diuretic, generate fluids to quench thirst, clear and penetrate lung heat and diarrhea of fire, and is suitable for the treatment of lung-heat cough, lung carbuncle (septicemia) with vomiting of pus, feverish gonorrhea and astringent pain (burning pain and stabbing pain during urination, accompanied by urinary urgency, and discomfort of abdominal tugging), gastric fever with vomiting and feverish diseases with vexation and thirst. Adverse effects and contraindications of rehmannia are not clear; caution should be taken for those with spleen and stomach deficiency (spleen and stomach weakness and cold). Rehmannia glutinosa is often used in combination with other traditional Chinese medicines, such as with Coix lacryma for the treatment of lung carbuncle cough and spitting of pus and phlegm; with Psyllium Hirsutum and Rhizoma Citri Root for the treatment of short and red urination (small amount of urination, dark yellow in color), and feverish lymphatic astringency and pain. If there is a need for medication, it should be applied under the guidance of a traditional Chinese medicine practitioner, and should not be used on its own.