Haemotympanum is blood behind the eardrum. It is diagnosed when the eardrum is examined with an otoscope. This is a magnifying glass with a torch attached which allows the eardrum to be seen. If blood is present behind the drum it is visible as it is only a thin membrane and light easily passes through.
A common cause of haemotympanum is a nosebleed. The nasal passage connects with the middle ear through the Eustachian tube. Blood can track back up the tube from the nose to the ear. This is particularly the case if the nose is packed to stop the bleeding. This is because the pressure in the nasal cavity is increased and it can be harder for the blood to leave through the nostrils or through the back of the nose.
Sometimes otitis media with effusion can cause blood behind the ear drum. This is often described as idiopathic which means that it isn't known what causes it.
Clotting disorders which can lead to bleeding may also cause haemotympanum. As the blood does not clot normally bleeding into the ear canal may not be controlled. Disorders of clotting may be heriditary or as a result of medication. Prescribed anticoagulants such as warfarin, aspirin or heparin can lead to problems with bleeding.
Tumours of the blood vessels in the ear canal are a rare cause of haemotympanum.
Other causes include a basal skull fracture. This is a break through the bottom part of the bone which surrounds the brain. As the ear canal and middle ear are part of this bone a fracture here can cause blood to appear behind the drum.
A basal skull fracture occurs due to trauma to the head. Other signs include headache, nausea, vomiting and visual disturbances. Drowsiness, seizures and coma can also occur if bleeding in the brain is associated.
This article does not comprise medical advice. Please visit a doctor if you have a problem with your ear or head.
Dr Toby Bateson, MD of ZenPlugs