Nostril blockage during sleep is common

When sleeping on one's side, many people experience the sensation of one nostril being blocked, which can switch sides as they move. This phenomenon is often normal and not a cause for concern.

The nasal cycle explains the shifting blockage

The shifting blockage is typically explained by the nasal cycle, a natural process where the nostrils alternate in how much air they allow to pass through. This cycle is controlled by the body’s autonomic nervous system.

Nasal turbinates control airflow

Inside the nose, structures called nasal turbinates contain tissues rich in blood vessels. These tissues can swell and shrink alternately, changing the airflow through each nostril. This process is what creates the nasal cycle.

Research confirms the nasal cycle’s role

A study published in PLOS One measured variations in nasal airflow and nostril dominance. The research also examined how posture affects the sensation, linking it in part to the autonomic nervous system.

Sleep position influences the sensation

According to the study, sleeping on one's side is associated with greater airflow in the upper nostril. This can make the sensation of a blocked nostril more noticeable, especially when lying down in a quiet environment.