The In-Check Nasal is a portable inspiratory flow meter, which measures nasal passage obstruction; this helps to indicate whether the patient is suffering from allergic rhinitis, which causes discomfort to sufferers. The device uses a simple measurement of how quickly the air can move through the nose when inhaling forcefully. This allows easy monitoring, on a daily basis, by the patient wherever they are and provides an accurate assessment of nasal congestion and response to treatment.