Nasal cycle explains why only one nostril feels congested

Dr. Amir Khan has explained the phenomenon of why nasal congestion often affects only one nostril at a time during a cold. This occurrence is attributed to the ‘nasal cycle’.

According to Dr. Khan, the nostrils alternate which side allows air to pass through to ensure they function effectively. This process involves blood vessels and tissues swelling on one side while the other side breathes normally. These roles switch every two to six hours, a mechanism that helps keep the nostrils healthy, maintains moist airflow, and allows for proper air filtration.

When experiencing a cold, individuals may notice mucus exiting from only one side, only for the congestion to shift to the opposite side a few hours later as the cycle progresses.