There are many reasons for feeling a foreign body sensation deep in the nasal cavity, and the common reasons are nasal inflammation, nasal polyps, nasal sinus tumors and so on. 1. Nasal inflammation: when the nasal cavity is inflamed, such as chronic rhinitis or sinusitis, the secretion can be increased, there may be a large number of dry scabs gathered in the nasal cavity, resulting in limited ventilation, thus appearing foreign body sensation. 2. Nasal polyps: Nasal polyps are smooth, soft, bulky organisms in the nose, which tend to clog up the nasal cavity and cause a foreign body sensation. 3. Nasal sinus tumor: when there is a nasal sinus tumor, the nasal passage will be occupied easily, which will make the breathing not smooth, and the symptoms of nasal congestion will appear, resulting in a foreign body sensation in the nasal cavity. If you feel foreign body sensation deep in the nasal cavity, it is recommended to consult a doctor in time to find out the cause and then standardize the treatment under the doctor’s guidance.