If you have ever felt like your head was underwater while battling a fever, you are experiencing a common flu symptom: ears popping. This sensation, often accompanied by a "full" feeling or muffled hearing, occurs because the flu virus causes inflammation and mucus buildup that blocks the . Why the Flu Makes Your Ears Pop

You can often encourage your Eustachian tubes to open and drain using simple techniques: Reducing Ear Pressure When You're Sick | Valley Audiology

Seek medical attention if:

When the tubes can't open properly to equalize pressure, you feel a "plugged" sensation. The "popping" occurs when a tube finally forces itself open momentarily to let air through. How to Relieve Ear Pressure at Home