Hi, thanks for using HCM. As allergy has already ruled out, other possible causes are sinus problem or vasomotor rhinitis. Consult ENT doctor for examination, Nasal endoscopy is useful to check for sinus, once sinus problem is ruled out, other probable cause is vasomotor rhinitis, which is basically due to dilatation of blood vessel in nose causing symptoms. Saline nasal spray, decongestants are useful, If your symptoms are not controlled with these measures then corticosteroid nasal sprays, antihistamine nasal sprays useful. Correction of any deviated septum, if present , is helpful in avoiding recurrence. If you are able to identify what causes your symptoms it may be possible to avoid these triggers, such as perfumes, secondhand smoke, dust, etc. Avoiding these triggers will reduce your symptoms and discomfort. You should also avoid overusing nasal decongestants. Hope this helps you. Regards