The air-filled spaces in your cheek bones, behind your nose bridge, and inside your forehead are called the sinuses. It’s a mess when they get inflamed. You can get drainage blockages, swelling, more mucus, and an infection.
Causes of a sinus headache. The pressure will cause a headache when your sinuses cannot properly drain. The swelling (inflammation) and increased fluid production lead to the pressure that causes a sinus headache. When there becomes stagnant fluid in the sinuses, viruses and bacteria can set up shop and cause infections. Most are due to viruses that occur for a week or less.