[2] According to Jason Turowski, MD of the Cleveland Clinic, "we are designed to breathe through our noses from birth—it's the way humans have evolved.

[5] In children, nasal congestion from enlarged adenoids has caused chronic sleep apnea with insufficient oxygen levels and hypoxia.

[6] Nasal obstruction characterized by insufficient airflow through the nose can be a subjective sensation or the result of objective pathology.

[12] According to WebMD, congestion can be addressed through the use of a humidifier, warm showers, drinking fluids, using a neti pot, using a nasal saline spray, and sleeping with one's head elevated.

[14] The Cleveland Clinic also states that congestion may be a sign of a deviated septum, a condition that needs to be addressed by a doctor.