Causes

The exact cause of nonallergic rhinitis is unknown.

Experts do know that nonallergic rhinitis occurs when blood vessels in your nose expand and fill the nasal lining with blood and fluid. There are many possible causes, including the nerve endings in the nose being overly responsive, similar to the way the lungs react in asthma.

Whatever the trigger, the result is the same — swollen nasal membranes, congestion or excessive mucus.

There are many triggers of nonallergic rhinitis, including:

• Environmental or occupational irritants. Dust, smog, secondhand smoke or strong odors, such as perfumes, can trigger nonallergic rhinitis. Chemical fumes, such as those you might be exposed to in certain occupations, also can be to blame.
• Weather changes. Temperature or humidity changes can trigger the membranes inside your nose to swell and cause a runny or stuffy nose.
• Infections. Viral infections such as a cold or the flu commonly cause nonallergic rhinitis.
• Foods and beverages. Nonallergic rhinitis can occur when you eat, especially when eating hot or spicy foods. Drinking alcoholic beverages also can cause the membranes inside your nose to swell, leading to nasal congestion.

• Certain medications. Medications that can cause nonallergic rhinitis include aspirin, ibuprofen (Advil, Motrin IB, others) and high blood pressure medications, such as beta blockers.

  Nonallergic rhinitis also can be triggered in some people by sedatives, antidepressants, oral contraceptives or drugs used to treat erectile dysfunction. Overuse of decongestant nasal sprays can cause a type of nonallergic rhinitis called rhinitis medicamentosa.

• Hormone changes. Hormonal changes due to pregnancy, menstruation, oral contraceptive use or other hormonal conditions such as hypothyroidism may cause nonallergic rhinitis.
• Sleeping on your back, sleep apnea and acid reflux. Lying on your back at night while you sleep can cause nonallergic rhinitis, as can obstructive sleep apnea or acid reflux.