Hematotympanum, or hemotympanum, refers to the presence of blood in the tympanic cavity of the middle ear. It can also be used to describe an ecchymosis of the tympanic membrane. This condition is characterized by blue-black discoloration of the tympanic membrane. Furthermore, the buildup of blood behind the membrane can cause bulging of the membrane. This condition causes conductive hearing loss and sometimes presents with facial nerve palsy or otorrhea in the context of other injuries.

There are many possible causes of hematotympanum. The most common causes typically involve trauma. Hemotympanum can be seen from cotton swab (eg, Q-tip) injuries and in the context of more severe head trauma where a temporal bone fracture is present. Barotrauma from diving or from flying are also common causes.

Another cause of hemotympanum is epistaxis, which can lead to eustachian tube dysfunction and retrograde blood flow into the middle ear cavity. Therapeutic nasal packing and surgical procedures such as septoplasty can also lead to retrograde flow of blood into the inner ear. Abnormalities of coagulation can lead to bilateral hemotympanum. This can be seen in the context of oral anticoagulation medications, conditions that affect the hematologic system such as leukemia and lymphoma, or chemotherapeutic medications.

A paraganglioma, a vascular tumor of the middle ear, can mimic the appearance of hemotympanum. Abnormalities of the carotid artery, including aneurysm or aberrant course through the petrous portion of the temporal bone, can also mimic the appearance of blood in the middle ear.

Given the variability of causes, this condition can affect people of all demographics and locations.