According to scientists from the Monell Center, the annoying feeling of nasal congestion is related to the temperature and humidity of inhaled air, perhaps more than anything else.
According to Dr. Robert Ivker, D.O., former President of the American Holistic Medical Association, the ideal level of relative humidity for sinus health is between 35-45%. The findings suggest that sensory feedback from nasal airflow contributes to the sensation of congestion.
Nasal congestion, usually caused by infection or allergy, is one of the most common medical conditions in the United States, afflicting approximately 33 million people and accounting for over $5.8 billion in healthcare costs annually. Nasal congestion and the associated feeling of obstruction is the symptom that typically and unnecessarily causes individuals to seek medical assistance.
Vasomotor rhinitis can actually be triggered by physical conditions such as strong odors, perfumes, changes in temperature and humidity, smoke, fumes and bright sunlight. Most patients experience a runny nose, post nasal drip and/or nasal congestion.
“By establishing that feelings of nasal congestion can be sensory-related, we open doors for more targeted treatment,” said study lead author Kai Zhao, Ph.D., a bioengineer at Monell. “For example, effective treatments may need to include a focus on restoring optimal humidity and temperature in the patient’s nasal airflow.”
In the study, published online in the free-access journal PLoS One, 44 healthy volunteers rated symptoms of nasal congestion after breathing air from three boxes: one containing room air at normal humidity, another containing dry air at room temperature, and the third containing cold air.
The volunteers reported reduced nasal congestion after breathing from both the cold air box and the dry air box as compared with the room air box, with the cold air box decreasing reports of congestion most effectively.
Calculations revealed that humidity also was an important factor, with lower humidity associated with decreased feelings of congestion.
Increasing the humidity in a dry room can help to prevent nasal congestion. According to Memorial Hospital, there are several ways to increase the humidity in a room. Take a hot shower and breathe in the steam to help loosen congestion and thin nasal secretions. If you want to add humidity to a room such as a bedroom or living room, buy a vaporizer that will release moisture into the air. If you are at work and unable to take a hot shower or add a humidifier to the room, make a hot beverage such as tea or broth. Cup your hands over the mug and breathe in the steam.
The authors speculate that temperature and humidity interact as air moves through the nasal cavity to influence nasal cooling. It is this cooling that is then detected by ‘cool sensors’ inside the nose to influence the feeling of air flow as being either easy or obstructed.
“Someone in the desert, all other things being equal, should feel less congested than someone in the jungle. In the low humidity of the desert, there is more evaporative cooling inside of the nose, such that the temperature of the nasal passages is lower. This leads to a feeling of greater air flow â€“ and less sensation of obstruction.” said co-author Bruce Bryant, Ph.D., a sensory scientist at Monell.
Future studies will examine patients reporting nasal obstruction to see if the sensory findings reported here can explain their symptoms, and also explore how sensory factors interact with other predictors of nasal obstruction.