1. Is it seasonal or perennial Allergy
2. Ayurveda believes Ama (Toxins) and Low Immunity level to be the prime cause of allergies.
3. elevate the head at night time to prevent nasal congestion
4. Avoid: dairy products,foods which are difficult to digest,cold
5. In yoga
you can go for breathing Exercises like : Anulom-Vilom Pranayam, and after few weeks start practicing Kapalbhati.
6. Practice nasal cleaning with water (Jal Neti) whose effects are encouraging in relieving symptoms.