Sinusitis is an inflammation of the sinuses, which are air-filled spaces located in the skull. This condition can occur when the sinuses become blocked due to infections, allergies, or other factors, leading to symptoms such as nasal congestion, facial pain, and a reduced sense of smell. There are two main types of sinusitis: acute and chronic. Acute sinusitis typically lasts for a short period, often following a cold, while chronic sinusitis persists for longer than 12 weeks and may require medical treatment. Both types can significantly impact daily life and overall well-being.