The sinuses are numerous air-filled spaces within the body’s skull and facial bones, centered on the nasal cavity and serving a variety of functions, including reducing the weight of the head, humidifying and heating inhaled air, increasing the resonance of speech, and serving as a folds to protect vital structures in the event of facial trauma. Humans have four paired sinuses that are aligned with the pseudo-complex columnar epithelium. Maxillary sinus: the largest paranasal sinus, located below the eye in the maxilla; frontal sinus: located above the eye in the frontal bone; septal sinus: formed by discrete air sacs in the sieve bone between the nose and the eye; and pterygoid sinus: located in the pterygoid bone. The functions of the sinuses are controversial, but they are involved in several roles: reducing the relative weight of the skull, increasing the resonance of sound, providing cushioning to relieve facial trauma, protecting sensitive structures from temperature fluctuations in the nose, immune defense, etc. The sinus area is susceptible to sinus cancer, and it is important to be aware when there is pain in the nose or behind the teeth, eyes become swollen, facial numbness, persistent nosebleeds, headaches, changes in voice, and double vision. In summary, sinuses are spaces or hollow areas in the body that lead to four paired paranasal sinuses around the nasal cavity. Usually the paranasal sinuses are filled with air; however, when infected and inflamed, these sinuses may be filled with blood, pus, and mucus, all of which can cause discomfort and pain.