When fluid builds up in the ear, the patient may have a condition called external auditory canal fluid, which is often caused by washing the hair, bathing, or swimming in water. Under direct vision, a suction device can be used to clean out the middle ear cavity, but some patients may develop a condition in which the fluid in the middle ear cavity is difficult to drain on its own. Patients often experience negative pressure in the middle ear and tympanic membrane invagination, and often need to improve the function of the eustachian tube with nasal hormone sprays and oral anti-inflammatory, anti-infective, and anti-allergy medications. Some of the fluid may gradually resolve on its own, but if necessary, the patient may need to undergo further tympanic membrane aspiration.