Most people breathe primarily through their noses. As anyone who has ever experienced a severe cold may recall, we take our ability to breathe freely through our nose for granted until this ability is compromised. Blockage of our nasal air passage can be uncomfortable, lead to sinus pressure, reduce our sense of smell, and also cause snoring or sleep disturbance (sleep apnea) at night.
The nasal passage on each side of the nose is bordered by the nasal septum, the wall of cartilage and bone that divides the nasal passage into two separate channels, and the side-wall of the nose. The side-wall of the nose contains the openings for the sinuses and the tear ducts, and three structures called the "turbinates." The turbinates help to regulate airflow through the nose, warm and humidify the air we breathe, and filter out particles of dust and dirt to prevent them from reaching the lungs. The lowest, or inferior, turbinate is the largest. It contains many blood vessels that allow it to act as a radiator, warming the air that flows by it.
Nasal blockage can occur from a number of different causes, can shift from side to side, and can vary in severity. To simplify our discussion, we will consider nasal blockage of two separate types - a constant or "fixed" blockage, and a changing or "variable" nasal blockage. By variable we mean blockage that can vary from side to side, and in degree either on its own, or with medications such as decongestant pills or nose sprays.
Fixed Nasal Blockage
A fixed nasal blockage can involve one or both sides of the nose, and does not improve with medications. This can be caused by a structural problem or a growth inside the nose. The most common structural problem is a deviated septum, in which the septum is deviated, or pushed over, to one side, thereby blocking the nasal passage. More often than not, there are irregularities of the septal bone or cartilage that partially or completely block both sides, rather than just one side. In many cases this may be caused by previous trauma to the nose. Treatment is by septoplasty surgery, that involves straightening the deviated portions of the bone and cartilage working through the nostril, which is usually performed under general anesthesia. More rarely, the turbinates may be unusually large or malpositioned, causing a fixed blockage. However as discussed below, blockage due to turbinates usually improves at least somewhat with medical treatment.
Fixed blockage may also be caused by a variety of growths that may occur inside the nose. The most common are polyps, which when present usually affect both sides of the nose. Polyps arise from prolonged inflammation within the nose or sinuses, and may grow in size and number to even fill the entire nasal passage. Polyps may be seen in patients with chronic sinusitis, allergies, and cystic fibrosis. Treatment usually requires treating the underlying condition that caused the polyps, such as allergy injections for treatment of allergies, and may also involve endoscopic sinus surgery. A one-sided fixed nasal blockage arising without a recent injury to the nose is concerning for a growth in the nose. Although nasal polyps can be one-sided, they are usually found on both sides. A number of benign or even cancerous growths may occur in the nose. Most benign growths can be removed using an endoscope, such that no incisions need be made on the face. Sinus cancers may require more extensive surgery, and/or chemotherapy or radiation treatments.
Variable Nasal Blockage
Variable nasal blockage may also involve only one side, but more often tends to involve both sides. All of us experience some degree of variable nasal blockage naturally, due to what is called the "nasal cycle." This is a process whereby blood flow, and thus congestion, varies from side to side on a 6-10 hour cycle. This is why most will notice that they breathe better through one side of the nose for part of the day, and the other side of the nose the rest of the day.
The turbinates are a common cause of variable nasal congestion. In fact, it is primarily congestion or enlargement of the turbinates that leads to the nasal blockage associated with the nasal cycle described above, as well as the common cold, or allergy. The turbinates may also swell due to position changes, in particular when the head is lowered lowered. This phenomenon may lead to noticeable congestion when one lies down to sleep. Congestion due to turbinate enlargement may be treated with medications, or more permanently by turbinate reduction surgery. The latter is usually done in the office setting under local anesthesia.
Variable nasal blockage may also be due to generalized swelling of the nasal lining tissues, as can also be seen with the common cold, a bacterial sinusitis, or allergy. Treatment in this case must be directed at the underlying cause.
Evaluation and Treatment of Nasal Blockage
As the previous discussion highlights, some causes of nasal blockage may be suggested by a patient history alone. However a thorough examination of the nasal passages is always necessary. This is first performed using a speculum, which is used to hold the nasal passage open to allow a direct view inside. In some cases a more in depth examination, using a lighted endoscope, may also be necessary. Depending on the findings of the examination and the possible causes of the blockage, your doctor may recommend further tests, such as allergy testing or Xrays of the sinuses. Depending on the severity of the blockage and the cause or causes identified, treatment may involve medications, or septoplasty or turbinate surgery.
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