What are Sinuses?
Sinuses are paired air cavities or air spaces (pockets) in the cranial (head) bones. And they are connected to the nose on the facial part of the skull where air passes and mucus drains... However sinuses are also referred to as "paranasal sinuses".
If the nasal passages are swollen extending to the ostium of the sinuses, air cannot enter the cavity and a vacuum is created. This causes the mucus membranes to be "tugged" away from the bones they line and hence produces pain.
The paranasal sinuses are joined to the nasal cavity via small orifices called ostia. These become blocked relatively easily by allergic inflammation, or by swelling in the nasal lining which occurs with a cold. If this happens, normal drainage of mucus within the sinuses is disrupted, and sinusitis may occur.
What is Sinusitis?
Sinusitis occurs when one or more of the sinus cavities become inflamed due to several causes such as bacteria, fungi and allergies to pollen, causing pain in the nasal area. The main symptom of sinusitis is pain and the location of this pain depends on which sinus is affected...
For acute sinusitis, symptoms include facial pain/pressure, nasal obstruction, nasal discharge, diminished sense of smell, and cough not due to asthma (in children). Additionally, sufferers of this disorder could incur fever, bad breath, fatigue, dental pain, and cough.
Cavernous sinus thrombosis is the blockage of a large vein at the base of the brain which causes a blood clot to form. The cavernous sinuses are situated behind each eye socket and on either side of the pituitary gland. Their purpose is to drain blood from the brain and face back to the heart.