When there are significant pressure changes in the environment and your sinuses are obstructed, you can develop a pain in the face or forehead that feels like a sharp stab, as if you were being attacked with a knife. This pain can be accompanied by a nose bleed: The negative pressure can tear a blood vessel or the membrane itself. This is called “sinus squeeze” because it feels as if someone were putting your sinuses into a vice and squeezing it hard enough to cause pain. Sinus squeeze most often occurs when scuba diving or sky flying in an airplane because of the great fluctuations in air pressure. However, it can also occur when you are driving or riding on a train through a mountainous area.
You may also experience this same sharp pain in your ear. Ear squeeze occurs when there is a closure of the eustachian tube(s), combined with pressure changes in the environment. The eustachian tubes allow us to equalize the pressure in our ears. We all swallow 12-15 times a minute. Each time we swallow, the eustachian tube opens up to equalize the pressure in the middle ear. When this no longer occurs properly, the ears develop pressure gradients. This can be exacerbated when you climb a mountain, fly in an airplane, ride an elevator in a tall building, or scuba or sky dive. This is the reason that you may experience difficulty popping your ears when you fly.
The pressure can get so severe that it can tear a vessel in the eardrum, causing bleeding into the eardrum or middle ear, or the blood can run from the ear canal itself. Although rare, you may experience temporary or long-term hearing loss, tinnitus (a ringing in your ear), or dizziness (vertigo, or spinning or loss of balance), if the trauma from the pressure change is severe enough. These symptoms can most likely be reversed if treated immediately, so it is important for you to see an otolaryngologist (an ear, nose, and throat (ENT) physician) who is experienced with this type of problem.