Plantain has the effects of clearing heat, diuretic and expectorant. It is suitable for conditions such as heat knot bladder, edema and low urine. Plantain, also known as dangdao, cow’s tongue grass, ground bile head, is the dried whole grass of Plantago ovata, family Plantagoceae. It is sweet in taste, cold in nature, and belongs to the liver, kidney, lung and small intestine meridians. Its effects are clearing heat and diuresis, expectorating phlegm, detoxifying and cooling the blood. It is used in treating heat knotting in the bladder, edema, dysuria (irregular urination), gonorrhea (cloudy urine and leucorrhea), epistaxis, cough with phlegm-heat, sore throat, carbuncle sores and poisons, and other conditions. The adverse reactions and contraindications of Plantago Ovata are not clear, pregnant women and people with kidney deficiency and essence slippage should be cautious. If you need to use the drug, it should be used under the guidance of a doctor, do not blindly self-medication, so as not to cause adverse reactions.