Acute sinusitis is an inflammation of the sinuses, which are air-filled spaces located in the skull. This condition often occurs after a cold or respiratory infection, leading to symptoms such as nasal congestion, facial pain, and a thick nasal discharge. It can affect anyone and is usually caused by viruses, although bacteria can also be responsible in some cases. Treatment for acute sinusitis typically includes rest, hydration, and over-the-counter medications to relieve symptoms. In some instances, a healthcare provider may prescribe antibiotics if a bacterial infection is suspected. Most people recover within a few weeks without complications.