The middle ear is connected through the eustachian tube at the back of the nasal cavity. Inflammation in the nasal cavity after a cold can enter the middle ear through the eustachian tube or the eustachian tube itself can become blocked due to inflammation, resulting in obstruction of middle ear ventilation. Because the eustachian tube is closest to the ear, the throat becomes inflamed and swollen, and you will feel a blockage in the ear. You can pinch your nostrils and hold your breath when puffing hard. If the effect is not good, please go to the hospital. Most people can get better on their own when the nasal inflammation subsides, provided they do not pinch and puff or blow their nose, as this can aggravate middle ear symptoms. Some people will develop otitis media, and if the symptoms do not improve after the cold clears, they should see a doctor for treatment. Otherwise, some of them will cause hearing loss and middle ear effusion.