Blocked Nose

Anatomy of the nasal cavity

The nostrils are the entrance into two separate narrow, long passageways with a high roof. Each nasal passageway is a triangular space about the size of your palm. These passageways are divided by a straight, flat wall of cartilage and bone called the septum.

The septum can grow unevenly which may cause a bend or spur that interferes with the normal airflow. The sidewalls of the nasal passageways have three thin, curved bones that are covered by tissue that contains many blood vessels.

 The sidewalls of the nasal passageways have three thin, curved bones that are covered by tissue that contains many blood vessels.  This tissue acts like a heater and humidifier for the air as it passes through the nose and are called turbinates.  As air passes over the turbinate tissues it is heated to body temperature, humidified and cleaned.

Whether the ambient temperature is 100 °F in the shade or 40 degrees below freezing and regardless of the prevailing relative humidity, the air that eventually reaches the lungs will be near body temperature, close to 98% humidity and will have been filtered clean of most particles and chemical pollutants.

When the nose is blocked by a deviated septum or enlarged turbinates, air must travel through the mouth.  The mouth is not well designed for moisturizing the air and it  will quickly become dry.

The nasal cavity should be distinguished from the sinus cavities (link) which are the bony air chambers surrounding the nasal cavity.  The role of the sinuses is less clear.  They do not directly affected our ability to breath through our nose.  They may simply help to lighten the weight of the skull.  Since they grow out of the nasal cavity, they must drain into the nasal cavities.  To avoid problems, air must also be able to flow in and out of the sinuses.
 

The nasal and sinus cavities are also lined with a soft tissue, called mucous membrane or mucosa. This tissue looks and acts differently than skin. It has a pink, wet surface. The pink color comes from many blood vessels and the moisture is supplied by two types of glands that make a watery secretion and a thick, sticky fluid. Together they mix to form mucus or phlegm. On a normal day the nasal glands produce a very large amount of mucus, estimated to be about a liter per day. There are also microscopic hairs (also called cilia) on the mucosa which move together in waves to move the mucus either to the front or back of our noses.

Dryness can affect the mucosa badly.  It results in sticky, hardened mucus which can cause nasal blockage and postnasal drip.  The mucosal surface can also crust, crack and bleed, resulting in nasal bleeding.  Sometimes the cells will change irreversibly.  This is a common problem, especially during cold, dry winter months.

Some people need nasal surgery because they have trouble breathing through their noses.  This problem is often treated by straightening the nasal septum (septoplasty) or by reducing the size of the turbinates (turbinoplasty) or both.
 
It is important that your physician knows if you have had previous nasal or septal surgery and that you discuss your expectations with the surgeon.

Deviated Septum

A deviated septum describes the condition when some part of the cartilage or bone of the central nasal wall is not straight. A crooked septum can make breathing difficult as well as contributing to snoring and sleep apnea.

Causes

It is very common for the septum to grow unevenly. The septum may develop a bowing, bend or spur (a piece of bone or cartilage that juts out like in the CT scan above). The septum can develop these asymmetries either due to injury (broken nose) or uneven growth of the septum. Remember that the nose enlarges significantly during puberty and it is common for the cartilage to grow so much that it bends or overlaps those points where it joins the bone (forming spurs).

The nose also loses some of its shape and strength with aging, causing the nasal tip to droop and nasal passageways to get more blocked. In general, a septoplasty is needed only when nasal breathing problems do not get better with other nonsurgical therapies.

• moistening the nasal cavity with a humidifier, a nasal saline (saltwater) spray or hypertonic nasal irrigation (link)
• elevation of the head (and lying on one’s back).
• treatment of allergies with antihistamines (link) or daily use of topical corticosteroids (link).
• Use of an internal or external nasal dilator (link)