Brief Answer:
Sinuses commonly refer to air containing hollow cavities around the nose

Detailed Answer:
Hi XXXX,
Thanks for writing in to us.

I have read through your query in detail.
Please find my observations below.

1. The commonest reference to sinus in medicine is to paranasal air sinuses which are air passages above and on either side of the nose. Sinuses are structures which are lined by a thin layer of cells and help in regulation of the temperature and humidity of the air we breathe through the nose.

There are two maxillary sinuses on either side of the nose in the cheek region. Above and behind the nose we have the ethmoid and sphenoid sinuses. Above the eyes we have the frontal sinus.

Infection might happen in the sinuses due to various reasons and this leads to thickening of the lining of the sinuses and collection of fluid within and this is known as sinusitis. The sinuses open in to the nasal cavity and infections also happen when the openings are blocked. Patients with sinus infections usually present with headaches and heaviness of head towards the end of the day. An ENT doctor treats conditions of the paranasal air sinuses.

2. The other less common reference for sinus is a blind ending tract under the skin. This is usually due to an infection that tracks along to the skin surface. This is treated by a surgeon.

3. I guess you asked information on the paranasal air sinus which is described above in detail.

Hope this answers your question. Please feel free to correct any oversight in my interpretation of your problems and discuss them in detail as per your requirements.

Hope your query is answered.
Do write back if you have any doubts.

Regards,
Dr.Vivek

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