A humidifier is one of the most commonly used remedies for treating a sinus infection. Humidifiers work by adding moisture to the air in your home, which can help thin out mucus and make it easier for you to breathe. Since mucus makes your sinus infection painful and uncomfortable, any tactic you can use to make it less of an issue will go a long way toward helping you feel better.
Using a humidifier with a cool mist helps thin out the mucus that can block the nasal passages, making it easier to drain when you blow your nose. When you have a sinus infection, the mucus that collects in your nasal passages is usually thick and sticky, but it becomes thinner and less dense when exposed to moisture.
If you live in a dry climate or have difficulty breathing through your nose for any other reason, using a humidifier can help clear up your nasal passages and give you more comfortable breathing.