Usually, secondhand smoke can be avoided by avoiding smokers and ventilating more. 1. Avoid smokers: The most effective way to avoid second-hand smoke is to avoid smokers directly. When someone is smoking around you, you can leave, go to other places with good air, and wait for others to finish smoking before going back. 2. More ventilation: more ventilation is also an effective way to avoid second-hand smoke, every morning after waking up, open the windows first, so that fresh outdoor air into the room, so that the turbid indoor air out to reduce the harm of second-hand smoke. And wipe down tables and floors to remove tobacco residue from the dust. Patients should seek medical attention if they have respiratory or other problems to avoid delays.