Swelling of the ear lying down may be caused by cerumen irritation, secretory otitis media and eustachian tube infection. 1. Cerumen irritation: When the patient’s cerumen is overproduced, it will accumulate in the external ear canal, causing swelling inside the ear. When lying down, the swelling of the ear will be relieved because a gap may appear between the cerumen and the inner wall of the ear after it moves. 2. Secretory otitis media: the patient is infected due to the invasion of bacteria or viruses and other pathogens into the ear, under the action of inflammation, the secretion in the ear will increase, when lying down the location of these secretions change, temporarily lifting the Eustachian tube to the infiltration of the status of the ear, so the ear swelling will be relieved when lying down. 3. Eustachian tube dysfunction: the patient’s body resistance is low or localized by inflammation, will lead to swelling of the mucosa of the Eustachian tube, the middle ear cavity air pressure can not be physiologically released, secretions are difficult to discharge that is produced by the ear swelling, lying down due to the effect of gravity edema dispersion, the Eustachian tube intermittent open, there will be ear swelling lying down on the situation. Other conditions can also lead to ear swelling lying down, it is recommended that patients have timely medical examination to clarify the diagnosis of discomfort.