It is a common experience to feel as though one nostril is more open than the other. This sensation reflects a natural and continuous physiological process within the nose. Rather than breathing equally through both nostrils, the body orchestrates a subtle shift in airflow. This alternating pattern is a normal function.
The Alternating Airflow
The phenomenon of alternating airflow between the nostrils is known as the nasal cycle. This cycle involves a coordinated swelling and decongestion of specialized tissues within the nasal passages. Deep inside each nostril are structures called turbinates, which contain erectile tissues. The autonomic nervous system, which controls involuntary bodily functions, directs blood flow to these turbinates.
As blood flow increases to the turbinates in one nostril, they swell, causing that nasal passage to become more congested and restrict airflow. Simultaneously, the turbinates in the opposite nostril deswell, opening that passage for easier breathing. This process gradually reverses. A complete cycle, from one nostril being dominant to the other and back, typically lasts for a few hours, though the duration can vary from approximately 25 minutes to several hours.
Why Our Nostrils Take Turns
The body alternates airflow between the nostrils for several physiological purposes. When one nostril is more open, it allows a higher volume of air to pass through rapidly. This increased airflow is advantageous for tasks requiring acute olfactory sensitivity, such as detecting faint odors, as it brings odor molecules quickly to the olfactory receptors.
Conversely, the more congested nostril processes air at a slower pace. This reduced airflow provides more time for incoming air to be warmed, humidified, and filtered before it reaches the lungs. The slower passage also allows the delicate cilia and mucous membranes lining the nasal passage to rest and recover from airborne particles and pathogens. This helps maintain the health and efficiency of these protective mechanisms.
How to Notice Your Nasal Cycle
Observing your own nasal cycle is straightforward. One method involves gently closing one nostril with a finger and then breathing through the other, noting the ease or difficulty of airflow. Repeating this on the opposite side will often reveal a noticeable difference in how much air you can draw in. This highlights which nostril is currently more open.
You can also become aware of your nasal cycle by paying closer attention to your breathing throughout the day. While the shift is often subtle, certain situations might make it more apparent. Lying on one side, for example, can cause the lower nostril to become more congested due to gravity, enhancing the feeling of one-sided dominance. During exercise or meditation, you might notice the asymmetry in airflow more clearly.
What It Means for You
The nasal cycle is a normal physiological process, indicating proper function of the nasal passages and autonomic nervous system. Experiencing one nostril feeling more open than the other is not a cause for concern or a sign of illness. This natural rhythm is a testament to the body’s self-regulation.
External factors can influence the nasal cycle, sometimes making it more noticeable. Conditions like allergies, a common cold, or changes in body position can temporarily alter blood flow to the turbinates, making one nostril feel more blocked than usual. Stress and physical exertion can also impact the nasal passages.