Nasal allergies or hay fever result from exposure to environmental allergens such as dust, pet dander, pollen and mold spores. Common symptoms include congestion, itching, sneezing, runny nose, post-nasal drip and throat clearing. In an article written by Joseph Nordqvist on Medical News Today, he lays out important information on symptoms, treatment, what hay fever is, home treatment, causes and outlook. View the entire article here.