My father has allergic rhinitis. What is it in a nutshell?

Nasal allergies. Allergic rhinitis occurs when airborne allergens like pollens, animal dander, and dust mites contact the lining of the nose of a sensitized individual causing acute symptoms like sneezing and itchy, runny nose and nasal congestion. Allergic rhinitis can worsen asthma and chronic sinus disease and can significantly impact sleep, job performance, school performance and overall quality of life.
Heyfever. Rhinitis is 2 words combined: rhino for nose and itis for inflammation. Allergic or allergy is the cause of the inflammation. Allergy is the body's over reaction to normally harmless substances like pollen, pets etc.