My sense of smell is not good. i can smell some odors just a little. i have allergies to pollen during march. are my allergies the reason. why?

Maybe allergies: A decreased sense of smell can be related to significant nasal congestion and obstruction from allergies during your allergy season. Another possibility for a decreased sense of smell is nasal polyps. While these are not cancerous, they can lead to nasal congestion, sinus infections, and be associated with Aspirin hypersensitivity. It would be helpful to have a thorough nasal examination.