The sinuses are air-filled spaces located within the bones of the face and skull. They are connected to the nasal cavity and help to lighten the weight of the skull, improve voice resonance, and produce mucus that keeps the nasal passages moist. There are four main pairs of sinuses: the frontal, maxillary, ethmoid, and sphenoid sinuses. These cavities can become inflamed or infected, leading to a condition known as sinusitis. Symptoms of sinusitis may include nasal congestion, facial pain, and headaches. Maintaining good nasal health can help prevent sinus issues and promote overall well-being.