Changes in Air Pressure

Your sinuses are air-filled cavities within your skull; sudden pressure changes can cause air to get trapped in them, which can lead to sinus pressure, pain, and congestion. This commonly happens during air travel, so its best to avoid flying when you have nasal and sinus congestion due to a cold or allergy. If you need to fly, ask your doctor if you should take a decongestant or a nasal spray first. Diving is another cause of sudden sinus-pressure changes. Diving can also force contaminated water from a pond or chlorinated water from a swimming pool into your sinuses and cause sinus problems.