The nose functions as a sensory organ, allowing the brain to interpret the scents of the world. The sense of smell plays a role in the sense of taste as well. The nose also functions as part of the respiratory system, as air enters the body through the two holes in the nose known as the nostrils. Mucus, a sticky substance, lines the inside of the nose. Mucus performs many functions including warming and moisturizing the air before it enters the bronchial tubes leading to the lungs and capturing dust, germs and other small particles. Conditions which cause an increased production of mucus can lead to a chronic stuffy nose.
Allergic Rhinitis
Allergic rhinitis, a condition which affects 1 in 5 Americans according to the University of Maryland Medical Center, occurs when the body's immune system overacts to an inhaled substance. Allergic rhinitis is divided into two classifications. Seasonal allergens, such as pollen, cause seasonal allergic rhinitis, also called hay fever. Allergens found throughout the year, such as dust and pet dander, cause perennial allergic rhinitis.
When allergens are inhaled the immune system reacts by releasing IgE, a specific type of antibody and histamines, chemicals which trigger inflammation. The release of these causes the nasal passages to become inflamed and increases the production of mucus, resulting in a chronic stuffy nose.
Sinusitis
Sinusitis describes a condition in which the sinuses, four pairs of cavities found in the skull, become infected and inflamed. The Centers for Disease Control and Prevention indicate that approximately 31 million Americans suffer from chronic sinusitis, as described by the National Institute of Allergy and Infectious Diseases.
Sinusitis often begins with a common cold which leads to a bacterial infection of the sinuses. The infections cause the sinuses to become inflamed which leads to mucus and air becoming trapped in the sinuses. Mucus trapped in the sinuses is unable to drain down into the nasal passages, resulting in a chronic stuffy nose.
Adenoiditis
The adenoids, two masses located high in the throat behind the nose, consist of lymph-like tissue and function as a first line of defense against foreign invaders. The adenoids, similar to the tonsils, take samples of particles entering the body risking their own infection to protect the internal organs. Adenoiditis occurs when the adenoids become infected causing them to enlarge resulting in a chronic stuffy nose. Those with adenoiditis have trouble breathing due to the nose being blocked.
Nasal Polyps
A nasal polyp is a noncancerous growth on the lining of the nose. Small nasal polyps often go unnoticed, but larger ones cause breathing difficulties and frequent sinus infections which lead to a chronic stuffy nose, according to MayoClinic.com.
