SINUS. Anatomically the term refers to a space filled with blood or air. The word is also used by surgeons to signify a dis charging track which will not heal and has in many cases a foreign body, or dead bone at the bottom. Popularly the expression "Sinus trouble" implies an infection, acute or chronic, of one of the air-containing cavities connected with the nose. The largest of these cavities (the antrum) is contained in the cheek-bone; the next in size in the forehead (frontal sinus) ; smaller cavities open into the back (sphenoidal sinus) and sides (ethmoidal cells) of the nose. (See NosE.) An acute infection of one or more of these sinuses is liable to follow a severe cold, influenza, or other acute infectious illness. There will be pain, often wrongly described as neuralgia, in the face, forehead or behind the eye, which usually comes on about the same time every day. There is sometimes discharge from the nose. The pain is caused by the discharge which collects in the sinus and cannot get out because of swelling of the mucous membrane covering the communication with the nose. Menthol reduces this swelling and thus relieves the pain. A piece of menthol the size of a pea may be placed in a jug of boiling water and the vapour inhaled through the nose. Radiant heat, e.g., a powerful electric light bulb, held close to the forehead or face, is also helpful.
A chronic infection of one or more of the sinuses may follow an acute attack or may be associated with chronic nasal obstruc tion or catarrh. An infection of the antrum may also result from
dental disease. Pain may be entirely absent. Sometimes, but by no means always, there is a thick discharge (pus) which may run back into the throat. A discharge from one side of the nose is suggestive of sinus disease. Sometimes the discharge has an un pleasant smell especially when it is derived from an infected antrum. Although causing few symptoms, or indeed none what ever, sinus trouble is important because an infected sinus may act as a "septic focus" and cause disease of the eye, ear, joints, stomach, or indeed of almost any other part of the body, or it may be the starting point of a troublesome neuralgia. Sometimes, especially in the case of the antrum, repeated washing out may result in cure. Usually however, operative treatment is required. This consists in enlargement of the opening into the nose so as to allow free drainage or more rarely complete obliteration of the sinus.
Sinus trouble is prevented by avoidance of colds and early treatment of nasal obstruction and catarrh and of dental disease. It is probable that living in hot stuffy rooms increases suscepti bility to sinus infection. (See OLFACTORY SYSTEM.) (S. HA.)