Using a humidifier with your therapy can reduce dryness and congestion and improve comfort because the airflow generated by CPAP therapy is often greater than what your body is accustomed to humidifying on its own. However, with proper humidification, you can reduce common symptoms like nasal congestion and dry throat. ResMed heated humidifiers add moisture and warmth to the air delivered by therapy devices, reducing the symptoms of dryness and congestion and improving comfort.