Allergy symptoms, such as sinus congestion, can cause the eustachian tube to become blocked with mucus, rendering it unable to equalize ear pressure and maintain balance in the body, and this can cause a feeling of dizziness. Histamines, which the body produces when it is allergic to airborne substances such as dust and pollens, cause allergy symptoms, notes Healthline.
The eustachian tube is a canal that connects the middle ear to the nasopharynx. It regulates the pressure in the middle ear and makes it equal to the pressure in the air outside of the body, states Healthline.
The eustachian tube opens with activities such as yawning and swallowing to allow air in to equalize the pressure. Swelling from sinus congestion can prevent the eustachian tube from opening, and this leads to a change in pressure, notes WebMD.
Dizziness is one symptom of a blocked eustachian tube. Other symptoms include ringing and popping noises in the ear, ears that hurt and feel full, and hearing problems, explains WebMD.
Blocked eustachian tubes often get better without treatment. Sometimes yawning and chewing gum helps to unblock the tubes, and patients may hear or feel a popping sound when the tubes open and the pressure equalizes. In some instances, surgery is necessary to unblock the eustachian tube, where the doctor can make a small cut in the eardrum to drain the fluid and insert a small tube in the eardrum, notes WebMD.