Tea brewed with duckweed has the auxiliary therapeutic effects of penetrating rashes and relieving itching, diuretic and reducing swelling, and sweating and relieving epidemics (relieving the body’s surface of evil qi by way of sweating). It should be noted that, floating pimple tea drink can play a limited medicinal effect, not self-medication, in order to avoid adverse reactions. The floating pimple is a plant plant purple pimpernel dried grass, cold, pungent flavor, to the lung, bladder meridian. It has the function of transmitting rash and relieving itching, sweating and relieving symptoms, diuretic and swelling. It can treat itchy rash, wind-heat cold, impenetrable measles, edema and urination. Floating pimple is often used with other traditional Chinese medicines, such as with cicadas, mint, used for wind-heat colds, measles at the beginning, impermeable, and so on. The adverse reactions and contraindications of floating pimple are not clear at present. It should be noted that it should not be used by anyone who is suffering from superficial deficiency and spontaneous sweating (frequent natural sweating due to weakness of the muscle surface). If there is a need for medication, it should be applied under the guidance of a Chinese medicine practitioner’s diagnosis, and should not be used on its own to avoid adverse consequences.