Causes of Non-Allergic Rhinitis
It is not known exactly what causes non-allergic rhinitis. Experts, however, think that when the blood vessels in the wings expand, the nasal lining is filled with blood and fluid, resulting in non-allergic rhinitis. There are a number of factors that cause blood vessels to expand abnormally or cause inflammation in the blood vessels. One possibility is that the nerve endings here may be overly sensitive, just as they are in asthma.
Whatever the trigger is, the nasal membranes are swollen and clogged in the end.
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