Pain at the base of the ear often results from inflammation caused by lesions in the ear, and patients may experience hearing loss, tinnitus, and in severe cases, deafness. In-ear diseases require attention and active medical treatment when such symptoms appear is the basis for prevention of the disease. It is not difficult to diagnose in-ear disease based on typical cases, but it is important to differentiate it from similar diseases as below to avoid misdiagnosis. The diseases that need to be diagnosed and differentiated are described below: 1. Herpetic tympanitis Suddenly, persistent stabbing pain occurs after the onset of sensation. 2. Acute purulent otitis media Ear pain is one of the main symptoms of acute purulent otitis media. It is often a complication of upper respiratory tract infection and starts suddenly. In severe cases, there is unbearable stabbing pain and throbbing pain. The pain is relieved when the eardrum is perforated and the secretions from the middle ear flow out. Because the disease is often accompanied by inflammatory reaction of the mastoid membrane, there is often pressure pain and percussion pain in the mastoid area. If the pain is not relieved after the discharge of pus from the middle ear, the possibility of acute mastoiditis should be considered. 3. Acute attack of chronic suppurative otitis media Chronic osteochondritis or cholesteatoma type otitis media, such as poor drainage of pus, ear pain with headache and fever during sexual attacks, suggest the development of intracranial and extracranial complications. 4.Pneumatic traumatic otitis media In the case of sudden changes in air pressure such as high altitude flight or diving, otitis media with ear pain, tinnitus and hearing loss can occur.