There is usually some amount of lack of knowledge amongst non medical persons regarding "sinus"
First of all it is not 'a sinus' but Sinuses - there are four pairs of para nasal sinuses in the human body.
Secondly, the statement "Doctor I have Sinus" makes no sense - Everyone has a Sinus - what you are probably referring to is an infection of the para nasal sinuses - a condition called "Sinusitis".
Thirdly most patients who say ' I have sinus' are usually found to have a nasal allergy or a simple Rhinitis. Sinusitis is a very specific diagnosis and is usually best left to the Specialist to diagnose.
So, what are these 'Sinuses'?
Para Nasal sinuses are air filled cavities surrounding the nose and there are four paired sinuses (one on each side) - Frontal, Maxillary, Ethmoid and Sphenoid Sinuses.
Though no clear role has been established to these sinuses, it is felt that they keep the weight of the skull bones light, help in ventilating the inhaled air as well as add resonance to the human voice.
Sinuses are as prone to Allergy and Infection as the rest of the nose since the mucosal lining of the two are in continuity with each other.
So how do we keep our sinuses healthy and clear?
1. Steam Inhalation - doing a good steam inhalation at night helps in clearing mucus and make you breath better - best time is to do it at night.
2. Breathing Exercises - whether you like to call them Yoga or just plain deep breathing exercises - they help in keeping your nasal passage clear
3. "Jal Neti" - a native Indian concept, the idea is to clear the crusts in the nasal passage by the gentle flow of water
4. Avoid visiting dusty, polluted areas
5. Use face mask if travelling through very polluted areas.