This is a common condition called ear barotrauma, caused by pressure imbalances behind your eardrum during descent. To prevent this, try yawning, chewing gum, or swallowing frequently. You can also gently blow your nose while pinching your nostrils closed. For medication, using a nasal decongestant spray containing oxymetazoline or taking an oral decongestant like pseudoephedrine 30 minutes before descending can help open your Eustachian tubes. Standard ear drops are generally not effective because the issue is behind the eardrum, but over-the-counter pain relievers like ibuprofen can help manage discomfort. If pain persists after descending, please see a healthcare professional.