The sinuses empty into the nasal passageways. Positioned along these passageways are long cone-like bony structures rich in blood vessels called the nasal turbinates. The turbinates are divided into the lower, middle and upper turbinates.
Similar to the nasal and sinus membranes, the nasal turbinates are coated with mucus. The turbinates serve multiple purposes including:
The blood vessels of the turbinates can widen and leak fluid into the nasal cavity in response to exposure to irritants and allergens. This results in swollen turbinates. If you complain of nasal congestion it is usually a result of swelling of the nasal turbinates. There is also a normal cycling of congestion and decongestion that occurs between the right and left nasal turbinates. When one side is congested, the other side is decongested. Most of the time you are unaware of the nasal cycle. However at times swelling can become extreme and lead to symptoms of severe congestion preventing air to enter the right or left side of the nose.
Chronic inflammation from allergies, irritants and other causes can lead to enlargement of the turbinates known as turbinate hypertrophy. This condition can cause blockage of the mucous outflow from the sinuses which increases the risk for infection.