Ear effusion can be auricular effusion or middle ear effusion, etc. It may be caused by exudative otitis media, auricular pseudocyst, nasopharyngeal carcinoma and other factors. 1. Exudative otitis media: it is a non-purulent inflammatory disease of the middle ear mainly characterized by conductive deafness and tympanic effusion, and can be clinically divided into two types: acute and chronic. It is mainly caused by the dysfunction of the eustachian tube, localized infection of the middle ear, and metamorphosis, which leads to the phenomenon of fluid accumulation inside the ear. 2. Pseudocyst of the auricle: it refers to the cyst-like elevation on the outer side of the auricle, which contains plasma exudate, and is a kind of aseptic plasma exudate inflammation within the cartilage. The cause of the disease has not been clearly defined, and it is considered to have a close relationship with trauma and mechanical stimulation. 3. Nasopharyngeal carcinoma: Nasopharyngeal carcinoma can press the Eustachian tube, which can lead to the formation of occlusion of Eustachian tube, inducing the appearance of tympanic effusion. There are many reasons leading to ear effusion, so it is necessary to actively seek medical treatment and find out the causes of the disease before reasonable treatment can be carried out under the guidance of doctors.