There are four pairs of sinuses (named for the skull bones in which they're located). Interactive diagrams show sinus cavity locations and help visualize sinusitis, the most common type of sinus ...

Your nose is part of your respiratory system that filters breasted-in air and assists with your sense of smell. Learn more about nose anatomy and functions.

Anatomy and Pathology There are 4 sets of sinuses ordinarily present in humans, but congenital absence or hypoplasia of one or more sinus cavities is not uncommon.

What is the coronary sinus? Read on to learn more about this important blood vessel in the heart, including its location, function, and role in different heart procedures.

Allergies, or allergic rhinitis, can also increase your risk of a sinus infection. If you do develop a sinus infection from allergies, you may experience a sinus headache along with other symptoms, ...

Sinus infections can be incredibly frustrating and often painful. Here are seven reasons you might be getting them more often than other people.

Sinus infections, when your sinuses are inflamed, may result from several causes, such as air pollutants, viruses, or allergies. Learn more.

WebMD helps you develop a plan to treat sinus problems that come from having allergies or a common cold.

The function of the paranasal sinuses is not clear, but theories include humidification and warming of inspired air, lightening of the skull, improvement of vocal resonance.