中耳炎是一系列中耳发炎疾病之统称。其中以急性中耳炎（AOM）和中耳积水两型最为常见（OME）。急性中耳炎为急性感染所致，耳朵疼痛为其常见的临床症状。罹患急性中耳炎的幼童，常有拉扯耳朵、哭声次数增加及睡眠品质不佳等情况，有时也会有食欲不振或发烧的情形。中耳积水一般没有症状，中耳积水的定义是在耳朵中有出现不是因为感染而产生的液体，时间已超过三个月以上。慢性化脓性中耳炎（CSOM）是指中耳发炎已超过二周，因此耳朵开始化脓，也可能是急性中耳炎后的并发症。中耳炎很少会疼痛，不过都会伴随着听觉障碍的情形。若是长期中耳炎造成的听觉障碍，会影响儿童的学习能力。中医称中耳炎为“耳脓”、“耳疳”，认为是因肝胆湿热（火）邪气盛行引起。

Otitis media is a group of inflammatory diseases of the middle ear. The two main types are acute otitis media (AOM) and otitis media with effusion (OME). AOM is an infection of abrupt onset that usually presents with ear pain. In young children this may result in pulling at the ear, increased crying, and poor sleep. Decreased eating and a fever may also be present. OME is typically not associated with symptoms. Occasionally a feeling of fullness is described. It is defined as the presence of non-infectious fluid in the middle ear for more than three months. Chronic suppurative otitis media (CSOM) is middle ear inflammation of greater than two weeks that results in episodes of discharge from the ear. It may be a complication of acute otitis media. Pain is rarely present. All three may be associated with hearing loss. The hearing loss in OME, due to its chronic nature, may affect a child's ability to learn.