The sinuses are hollow pockets in the skull that can fill up with mucus when infected and usually drains out of the nose. Each sinus is covered with a mucous coat, which can become inflamed and swollen, blocking the flow of mucus out of the sinuses. The build up of mucus leads to sinusitis.
Sinusitis affects many people including children. There are 2 types of sinusitis:
- Acute sinusitis, also known as acute rhinosinusitis
- Chronic sinusitis, which lasts for at least 8 weeks even with treatment