Bird’s nest cannot be used to relieve cough and phlegm because bird’s nest does not have the effect of relieving cough and phlegm. Bird’s nest is a food and a health product, which is made from the saliva secreted by rainbows and other golden swiftlets. Mixed with other substances to form the nest, it is rich in some sugars, organic acids and free amino acids, and contains the characteristic substance sialic acid, but neither of them has the effect of relieving cough and resolving phlegm, so bird’s nest cannot be used to treat cough. When a patient has a cough, other medications are needed to relieve it, such as dextromethorphan to stop the cough and tranylcypromine hydrochloride for expectoration.