During air travel or when driving in the mountains, you should experience a popping in your ears. Your ear naturally regulates internal air pressure to protect itself from damage. If your ear isn't popping on its own you'll feel intense pressure and pain in your ear. Regularly popping your ears isn't safe, but at times, manual pressure release is necessary.
In your middle ear a tube called the Eustachian tube connects to the back of your sinus. Air and fluid can pass through this tube to regulate pressure behind your eardrum. If your Eustachian tube becomes blocked or if external air pressure changes rapidly, pressure builds up behind your eardrum. Built up pressure in your middle ear causes your eardrum to expand. If the pressure is not released, it will rupture your eardrum.
Your middle ear also contains three small bones needed for hearing. Blowing your nose forcefully in an attempt to pop your ears could cause one of those tiny bones to break. Your bones become brittle as you age, making forceful ear popping even more risky if you are older.
The safest way to pop your ears is by yawning, swallowing or chewing. If pressure needs to be released in your middle ear you'll hear a pop when you yawn or swallow.
If you plug your nose and blow you'll feel the pressure change in your ears. Although you can pop your ears this way, you can also rupture your eardrum using this method. You may temporarily feel as if you can hear better after plugging your nose and blowing, but doing so on a regular basis isn't safe.Only as a last resort should you plug your nose and gently blow to pop your ears.
If you're not travelling to or from higher elevation but still feel like you need to pop your ears, you could be suffering from Eustachian tube dysfuntion. Chronic allergies can also cause ear pressure and Eustachian tube blockage. If your ears continually plug up, there's probably a medical explanation. Consult your physician.