The eustachian tube is a tube that links the nasopharynx to the middle ear.It is horizontal in children and at an angle in adults.Enlarged adenoids, frequent episodes of common cold can block this resulting in the buildup of fluid in the middle ear. Usually the fluid is thin and the condition is called serous otitis media and it heals with treatment without complications. If the condition is recurrent or the fluid is thick , the tiny bones of the middle ear responsible for carrying sound waves by vibration cannot function properly resulting in fluctuating conductive hearing loss . If treated early, complete recovery is possible. Hence if a child has frequent episodes of cold and he has pain in the ear or shows any sign of decreased hearing, a complete E.N.T. check up can prevent the hearing loss and resulting speech and language problems.