Lemon leaves are used to relieve phlegm and cough, to regulate qi and stomach, and to stop diarrhea. In clinical practice, lemon leaves can be used to treat coughs caused by pneumonia, as well as stomach pain, gastritis, hernia and diarrhea. The most important effect of lemon leaf is that it improves one’s physical condition and is especially suitable for long-term consumption. The composition of lemon leaves is complex and contains a variety of substances that are beneficial to human organs, which can eliminate the damage of viruses to human internal organs, reduce the occurrence of diseases, and enhance one’s constitution, and the method of use is also relatively simple, as one can directly drink lemon leaves as tea. Also, lemon leaves are effective as a daily health supplement and medicine for chronic coughs and temporary coughs that occur after a cold.