Untreated Sinus Infection and the Possible Further Risks Untreated sinus infection can lead to a bigger and more serious issue. Sinusitis infection, or also known as sinusitis, can be ranging in severity – from mild to severe. In mild cases, you can use natural remedies or over the counter medicines. Feel free to use decongestants, nasal irrigation, and steam inhalation to treat the issue. However, if the sinusitis happens for weeks, or even months, you…