Rehmannia glutinosa, maitake and yam tea drink should not be drunk for a long time. Rehmannia glutinosa, Ophiopogon as well as Chinese yam are commonly used Chinese herbs in clinical practice. Since any Chinese herbs have to go through the liver and kidneys for detoxification, decomposition and metabolism, etc., long-term use of these herbs may cause damages to the corresponding parts of the body, so even if rehmannia glutinosa, Ophiopogon, and Chinese yam are made into a tea drink, it should not be consumed for a long period of time. Reed root is the fresh or dried rhizome of reed, family Gramineae, which has the effect of clearing heat and fire (removing heat and fire from the body), generating fluids and quenching thirst (promoting the production of fluids to quench thirst), and it can treat fever and thirst, lung-heat coughs, and carbuncle spitting pus. Maitake is the dried tuberous root of Maitake, family Liliaceae, which is effective in nourishing yin and generating fluids, moistening the lungs and clearing the heart, and can treat dry lung and dry cough, cough with deficiency of yin and consumptive cough, paralysis of the throat (redness, swelling and pain in the pharynx or dryness, with a sense of foreign body, or itchy discomfort in the pharynx and difficulty in swallowing), and thirst with injury of fluids, and other symptoms. Yam is the dried rhizome of the plant Dioscoreaceae, with the effects of tonifying the spleen, nourishing the stomach, generating fluids, benefiting the lungs and tonifying the kidneys and astringing the vital essence, it can treat symptoms such as deficiency of the spleen with low food intake, prolonged diarrhea, coughing and wheezing in the lungs, spermatorrhea in the kidneys, and frequent urination. It should be noted that rehmannia should be taken with caution for people with spleen and stomach deficiency (spleen and stomach weakness and cold), maitake is prohibited for people with spleen and stomach deficiency and diarrhea, wind-cold and cold, as well as phlegm-dampness coughing and wheezing, and yam is prohibited for people with dampness in the middle of the body (dampness that is too heavy and leads to fullness and discomfort in the spleen and stomach) or those who have solid evils or accumulation of stagnation. It is recommended that patients should take the tea under the guidance of a doctor, and the specific time of taking the tea should also follow the doctor’s instructions.