Sinus headaches can cause a gnawing pain behind the nose and eyes. The pain most often gets worse in the afternoon and evening. You may also run a fever. Sinus headaches are caused by colds or allergies that make the nasal passages inflamed or infected.

Treat colds promptly to keep mucus from backing up.
Avoid things that trigger sinus problems, such as pollens, dust, smoke, fumes, and strong odors.
Take allergy medications as directed by your doctor.
Keep your sinuses open and free of mucus.
Use a nasal decongestant as directed to reduce the inflammation.
Drink fluids to keep the mucus thinner. This helps it drain more easily. You can also use a humidifier.
Apply hot packs to the area around your sinuses. Use a hot water bottle.