Rhinitis has many possible causes. Rhinitis can be either acute orchronic, and is categorized into three areas: allergic rhinitis, non-allergic rhinitis, and mixed rhinitis, which is a combination of the previous two. Allergic rhinitis is the most common cause of rhinitis in the world. It is caused by environmental allergies and is characterized by an itchy/runny nose, sneezing, and nasal congestion. Other allergic symptoms include:
1. Itchy ears and throat
2. Eustachian tube problems
3. Red/watery eyes
4. Cough
5. Fatigue/loss of concentration/lack of energy from loss of sleep, and headaches or facial tenderness

People with allergic rhinitis also have a higher incidence of asthma and eczema, which are also mainly allergic in origin.
Seasonal allergic rhinitis (hay fever) is usually caused by pollen in the air, and sensitive patients have symptoms during peak times during the year.
Perennial allergic rhinitis, a type of chronic rhinitis is a year-round problem, and is often caused by indoor allergens, such as dust and animal dander in addition to pollens that may exist at the time. Symptoms tend to occur regardless of the time of the year.