The keywords of the definition are:
'Paranasal' which which means close to the nose.
The sinuses are air-filled spaces in the bones of the area around the nose. The sinuses are small areas that are difficult to access and treat, especially, when the disease has been ignored and has worsened. While healthy sinuses contain air, infected sinuses feature fluid, a breeding ground for harmful bacteria.
Inflammation means redness and swelling due to infection (invasion of germs) or other reasons.
Nasal congestion occurs due to the blockage of nasal passages, causing a 'stuffy nose'.
(anterior/posterior nasal drip)
Nasal discharge is when the nasal cavity is filled with mucus. It's usually known as 'runny nose'.
When sinuses are blocked, pressure increases significantly and produces facial pain.
Occasionally, when the sinuses are acutely inflamed or blocked, it may affect the sense of smell.