There is a very unpleasant odor whenever i sneeze although i don't have a bad breath. what could be the reason? thanks

Sinus: Your sinuses could be the source. Mild sinus infection is possible with only occasional bad taste or odor. Sneezing or bending over can be the trigger, making it noticeable.

Sinus infection: Possible sinus infection. If so you need to be on antibiotics.

Sinusitis: The likely cause is an infection in your sinuses. I would refer to an ent. Doctor for follow up if it persists. Antibiotics tend to fix the problem.