White-flowered Xiaku Cao has the effect of clearing heat and calming the liver, and is mainly used for treating lung-heat coughs and other conditions, as well as high blood pressure in modern medicine. White-flowered Xiaku Cao is the whole grass of Heterophyllum glabrum, family Labiatae, also known as white-flowered sweet nectar. Its flavor is bitter and cold in nature. It has the efficacy of clearing heat, calming the liver and relieving cough. In clinic, it can be decocted or put into pills and powder to treat cough, asthma and nasal agitation caused by lung heat, and it can also be used in modern medicine to treat high blood pressure, lymphadenitis and other diseases. This drug is cold in nature, so patients with deficiency cold of spleen and stomach (weak and cold spleen and stomach) should not use this drug. The adverse reactions and contraindications of this drug are not clear. Patients who need to use this drug should go to the hospital, under the guidance of the doctor, not unauthorized use of drugs, to ensure the safety of drug use.