Acute sinusitis is an acute inflammatory response of the sinuses caused by a sudden bacterial infection. Clinically, the most common sites of lesion are the maxillary sinuses and ethmoid sinuses, though some patients may also experience inflammation in the frontal sinuses or sphenoid sinuses. The main symptoms include sudden nasal congestion, purulent nasal discharge, headaches, dizziness, and reduced sense of smell. If the inflammatory response is particularly severe, it may also affect vision or cause fever and a feeling of heaviness in the head. Overall, it is considered to be an acute inflammatory response, primarily treated clinically with antibiotics to counter the infection, along with the use of nasal sprays and nasal irrigation, typically with saline solution. Regular follow-up checks are required, and the recovery period generally lasts about one to two weeks. (Medication should be used under the guidance of a doctor based on specific circumstances.)