Nasal congestion is the most common side effect of CPAP therapy. A runny, itchy or dry nose, or nosebleeds may also occur. Nasal congestion often subsides after the first month. It also tends to be more common among people with OSA. This congestion is not always a result of CPAP and is likely to happen in the colder months and during allergy season. We recommend consulting your doctor if your congestion is severe, or if you have nasal, sinus or ear pain. Here are three steps you can take to mitigate nasal problems: