I myself feel a foul odor in the nose, more so in the morning . What could be the cause. Could it be related to a slight swelling in the gum which is not painful. Tooth is also not loose.

Yes this is what you are smelling. I would suggest you do see a dentist and have an x-ray taken of the tooth to see just what the extent of the gum infection is. You are smelling the infection. You may need an antibiotic or have a possible tooth infection way down in the bottom of the tooth. Any swelling of the gums is never a good sign.