Pus in the ear is commonly known as “rotten bottom of the ear”. It’s really common. Most people don’t think it’s a big problem. In fact, there are three types of otitis media: simple, osteochondritis, and cholesteatoma. Simple otitis media is the most common type and is caused by recurrent upper respiratory tract infections and the retrograde movement of pathogenic bacteria through the eustachian tube to the middle ear. The pus that flows from the ear is like mucousy nasal discharge, which is usually odorless, and the pus flows and stops. The condition may vary from time to time. This type of lesion is mainly located in the mucous membrane layer of the middle ear, and there is usually no granulation or polyp formation, so it is also called the mucosal type. When the mucosa is infected and inflamed, it should be treated promptly and appropriately, and the tympanic membrane perforation should be drained freely. The inflammation can be effectively controlled. There is no major problem. Ossicular otitis media is a more severe form of otitis media, with more pus flowing from the ear and lasting for a long time, with blood in the pus or bleeding in the ear. In severe cases, various complications can also occur. It is necessary to keep the drainage open, use local medication to promote dryness of the ear, and conduct regular reviews, including CT examinations. If the drainage is poor or if complications are suspected, surgical treatment is required, and it will not be possible to solve the problem just by taking some medication or ordering some drugs. Cholesteatoma is the most serious type of otitis media. The so-called cholesteatoma is not a real tumor, it is because the loose part of the tympanic membrane has been sunken and perforated for a long time, and the epithelial cells of the external ear canal have grown into the middle ear cavity, and because the inflammation does not heal for a long time, the vitality of these epithelial cells is enhanced, and the layers of shed epithelium gradually accumulate and increase in size, compressing and invading the surrounding bone, causing bone resorption and destruction. The central part of the “tumor” decomposes and necroses due to lack of nutrition and produces bad odor, which is named cholesteatoma because it contains cholesterol. Cholesteatoma can destroy bone and lead to intracranial and external infections such as meningitis, brain abscess, facial paralysis, vertigo, and even life threatening. Therefore, once a cholesteatoma is diagnosed, in principle, it should be operated promptly. Chronic suppurative otitis media is a common disease, and timely treatment and active prevention are the keys. 1. Thoroughly treat acute suppurative otitis media to protect the integrity of the eardrum and reduce the incidence of chronic suppurative otitis media. 2. Quit smoking and drinking and try to avoid colds. Recurrent episodes of upper respiratory tract infections, which cause pathogenic bacteria, can lead to middle ear infections via the eustachian tube upstream, thus inducing otitis media. At the same time, some patients with chronic suppurative otitis media are accompanied by tinnitus, either in the form of high-tone cicada-like tinnitus or low-tone rumble-like tinnitus. Staying up late, smoking and drinking can often aggravate the symptoms of tinnitus, so it is necessary to quit smoking and drinking. 3. For those with old tympanic membrane perforation and tympanic membrane placement, swimming must be prohibited and water must be prevented from entering the ear when washing and bathing to avoid inducing infection. In conclusion, chronic suppurative otitis media should not be ignored, and once diagnosed, it is reasonable to consult the relevant department early and seek early intervention by professionals to prevent long-term complications such as tympanosclerosis and tympanic membrane adhesions.