Hi dear , The doctor is right , it usually occur due to upper respiratory infection like cold . There are other causes also like sinusitis and post nasal drip . Due infection the mucus goes into eustachian tube which actually causes such symptoms , this condition is known as Eustachian tube dysfunction ( ETD) . The eustachian tube balance the pressure between middle ear and oropharynx when it get blocked or partially blocked then such symptoms arises . Doctor may prescribe antibiotics or antiviral drugs depending upon the diagnosis . Doctor may also prescribe decongestants and mucolytic agents . Take steam twice a days , do warm saline gargles and try to keep your ear dry . Hope your concern has been resolved. Get Well Soon. Best Wishes, Dr. Harry Maheshwari