Non-allergic rhinitis
Non-allergic rhinitis (sometimes called chronic rhinitis) can look a lot like hay fever: a stuffy or runny nose, postnasal drip, sneezing. The difference is the mechanism. Allergic rhinitis is IgE-mediated — the immune system is reacting to pollen, dust mite, pet dander, or mold. In non-allergic rhinitis, skin tests to those allergens are typically negative. The nose is still inflamed, but the trigger is not an IgE allergy.
Common irritant triggers include weather changes, strong odors, smoke, perfume, and other airborne irritants. Some people have mixed rhinitis: allergic and non-allergic components together. Sorting that out is why testing and history both matter. See allergic rhinitis for the IgE-driven picture.
Nasal sprays are often part of treatment for both kinds of rhinitis. Technique still matters — most people spray the septum and then stop the medicine. The full walk-through is on the allergic rhinitis page: How to Use a Nasal Spray Correctly.