Smoking across the bridge means that when smoke passes through the throat, mouth and lungs, the whole process is mainly inhalation of gas, and the smoke is heated, while the content of harmful substances such as nicotine in the smoke is relatively low.
However, relapse refers to inhaling smoke when smoking, and then immediately inhaling air, which usually makes the smoke stay in the mouth, throat and lungs for a longer time, so that harmful substances such as nicotine have more time to be absorbed and the intake of harmful substances such as nicotine is increased, which is relatively harmful to the body.
Generally speaking, the way of returning smoke across the bridge will affect the intake of nicotine and other harmful substances in smoke, which will have different effects on health. When smoking, it is suggested to choose a safer way to smoke, so as to reduce the inhalation of harmful substances.