Our ears contain small tubes, called Eustachian tubes, that connect the ears to the back of the throat. Fluid in the ear is caused when there is something that prevents the tubes from draining properly, which can include:
Colds, sinus or throat infections
Pressure in the ears
Visual inspection (otoscopy) by an audiology or medical professional is the first step to identifying fluid in the ear. A test called tympanometry, which can be performed by an audiology professional, can also determine if the eardrum can move - if there is fluid present, the eardrum won't move.
Treatment and prevention
Fluid in the ear will usually resolve on its own, without the need for any treatment. If the tube blockage is caused by inflammation or an infection, your GP may prescribe a course of antibiotics to reduce the swelling of the Eustachian tubes and encourage the fluid to drain away.