Seasonal allergic rhinitis (hay fever) is most often caused by pollen. Perennial allergic rhinitis is triggered by common indoor allergens.
It is most often caused by different trees, grass and weeds pollen carried in the air during different times of the year in different parts of the country.
Many people with allergic rhinitis are prone to have eye allergy(allergic conjunctivitis)
In addition, allergic rhinitis can make symptoms of asthma worse for people who suffer from both conditions: allergies and asthma.