In case of uncertain pain of the frontal, nasal and maxillary area one must search for disturbed ventilation of the nose or its communications. Particularly so, if no radiological evidence is found. Anatomical changes may cause a primary irriation of the mucosa, when ventilation is distirubed or when there is direct contact between septum and conchal mucosa. As a reaction to such primary disturbance, ventilation to the maxillary sinuses may be inhibited, thus causing a secondary irriation. Thus a recidivating acute maxillary pain may occur without a real sinusitis, because of a hypoxia of the sinus. Rhinoscopy resp. nasal endoscopy will clear up anatomical primary causes. Conchal contact should be eliminated by lateroposition or by pinching. The septum deviation should be corrected if by nasal drops or spray the pains may be eliminated. Sinus obstruction may be diagnosed by rhinomanometry and sinuscopy and may be simultaneously treated by a small drainage tube.