Drinking more water for a cold and cough is useful. Because a cold is an inflammatory reaction in the mucous membrane of the upper respiratory tract, caused by the invasion of pathogens in the body, resulting in congestion, edema and exudation of a large amount of inflammatory secretions, containing a large amount of shed tissue fragments, as well as dead and live pathogens, and the metabolites of their inflammatory reaction. Drinking more water facilitates the removal of these substances from the body as soon as possible through the excretion of phlegm, which can promote the recovery of the inflammation of the cold and relieve the symptoms of cough. Moreover, drinking more water can enhance the body’s metabolism and immune function response, and excrete the inflammatory substances as soon as possible. And if it is accompanied by fever, it can also lower the body temperature and relieve the symptoms by taking away the body heat through urination and sweating. Therefore, it is beneficial to drink more water when you have a cold and cough.