Runny Nose

A runny nose (also called rhinorrhea by medical professionals) can be due to a number of conditions, many of which result in chronic rhinitis. Chronic rhinitis is inflammation or irritation of the inside lining of the nose (nasal mucosa), and/or an imbalance in nerve signals, which may be sending too many cues to your nose, telling it to drip, run and swell more than necessary. Over 24 million Americans suffer from chronic rhinitis, a condition that typically leads to the following symptoms:

  • Frequent watery, runny nose
  • Post nasal drip (excessive mucous dripping from the nose into the throat)
  • Nasal congestion and stuffiness
  • Persistent throat clearing

Anatomy

The nasal mucosa, lines the entire inside of the nose from the nostrils to the upper section of the throat. A layer of mucus sits on top of the outermost layer of the nasal mucosa. Meanwhile, one layer of the nasal lining itself consists of microscopic glands (which secrete the mucus), in addition to nerves, and an extensive network of blood vessels which can engorge with blood causing swelling of the nasal lining leading to nasal congestion/stuffiness. The nasal mucosa is, in many respects, the body’s first line of defense against foreign substances, playing a key role in the body’s immune responses to allergens (substances that trigger allergic reactions) and infectious particles which may otherwise spread to other important parts of the body such as the lungs. The mucus secreted by the nasal mucosa is sticky, and thus provides a physical barrier against attack by harmful viruses and bacteria by trapping these microorganisms, which are then attacked by the individual’s anti-bodies and enzymes which help break down invading organisms.

Causes of Runny Nose

There are many conditions which can lead to an excessively runny nose. Naturally, when your body is fighting off a virus (such as that during the common cold or the flu), or a bacterial infection (such as that during bacterial sinusitis), the nasal mucosa begins to produce more mucous as part of the immune response. However, in some individuals with environmental allergies, the body mistakenly recognizes harmless allergens (such as pollens, mold spores, animal dander, and dust mites) as potentially harmful intruders, and the nasal mucosa responds similarly with inflammation and increased mucous production; this condition is called allergic rhinitis. Non-allergic rhinitis is typically due to an imbalance in the body’s signals to the nose to produce mucous during exercise or for other unknown reasons (vasomotor rhinitis), or due to stimulants which can also cause the lining of the nose to become inflamed and make more mucous via different mechanisms, including direct irritation. This includes strong odors, cold temperatures, alcoholic beverages, cigarette smoke, air pollutants, certain foods (such as spicy foods), and even incorrect over-usage of certain medications such as decongestant nasal sprays. Furthermore, hormonal changes have been shown to lead to rhinitis, such as that during pregnancy.

Treatment

In order to best treat a runny nose, the underlying cause contributing to symptoms should be identified and treated, if possible. For example, patients with allergic rhinitis can be treated with allergen avoidance (e.g. staying indoors/keeping windows closed during high pollen counts), nasal steroid and antihistamine sprays, oral antihistamines, and other prescription medications that lessen the body’s response to allergens. When these treatments fail over the long-term, some patients may benefit from allergy shots. On the other hand, conditions like the common cold caused by a viral infection typically do not require treatment with medications other than perhaps those used for temporary symptom control. Colds typically worsen for a few days and can last for several weeks in some instances. Because they are caused by viruses they do not respond to antibiotics like bacterial sinusitis. However, individuals with the common cold can take over-the-counter medications to reduce symptoms, such as guaifenesin which thins mucous. Furthermore, it is important to rest as much as possible, drink plenty of fluids, especially water, and use saline nasal spray to help relieve symptoms until the cold has passed. By contrast, bacterial sinusitis often requires treatment with antibiotics, best prescribed after a bacterial infection has been confirmed by a physician such as an Otolaryngologist who can look directly into the nasal cavity to distinguish this from other causes of rhinitis. For other causes of non-allergic rhinitis, prescription ipratropium bromide nasal spray may be effective; this medication is an anticholinergic nasal spray that directly decreases secretion of mucous from the glands in the lining of the nose. Newer treatment options are also emerging, such as cryotherapy treatment, where a device can be used during an office procedure to deliver cold temperatures to the out of balance nerves in the back of the nose, interrupting the signals being sent to the glands in the nasal lining to make excessive mucous.