Nostril flaring, or nasal dilation, is a muscular action that widens the nasal aperture. This movement functions to increase air intake or serves as a subtle form of non-verbal communication. Performing this action intentionally requires isolating and controlling small, often underutilized facial muscles. Gaining voluntary command over this physical trait involves understanding the nose’s anatomy and engaging in deliberate practice.
The Muscles Responsible for Nasal Dilation
The physical act of pulling the sides of the nose outward and upward is managed by a small group of paired facial muscles. The primary muscle involved in active nasal dilation is the Levator labii superioris alaeque nasi (LLSAN). Its Latin name translates to the “lifter of both the upper lip and of the wing of the nose.”
The LLSAN runs along the side of the nose, originating near the eye and inserting into the skin of the nostril and the upper lip. This connection explains why people often inadvertently move their lip or cheek when attempting to flare. A secondary contributor is the Nasalis muscle, specifically its alar part (sometimes called the dilator naris posterior). This part of the Nasalis muscle depresses the side of the nose laterally, widening the nostril opening during contraction. Both muscles are controlled by the facial nerve (Cranial Nerve VII), allowing for their use in dynamic facial expressions.
Mastering the Voluntary Flare
Achieving conscious control over nasal dilation begins with muscle isolation, requiring focus and the use of a mirror. Start by using visualization, imagining the sensation of trying to smell a faint scent, which naturally engages the necessary muscles slightly. This initial focus helps create a mind-muscle connection before attempting a full contraction.
A technique known as the “press-and-tighten” method helps isolate the movement. Place your index fingers gently on the sides of your nose, near the crease where the nostril meets the cheek. Gently press inward while simultaneously attempting to flare your nostrils outward against this resistance. This training helps you feel the precise muscles contracting without relying on larger, surrounding facial muscles, such as those used to lift the eyebrows or smile.
Once you feel the contraction, try to replicate the outward movement without your fingers. A common difficulty is the inadvertent lifting of the upper lip or cheek, since the LLSAN muscle connects to both the nostril and the lip. Sustained practice can involve trying to move just one nostril at a time, which is an advanced form of isolation. Consistent, short practice sessions in front of a mirror reinforce the neural pathways needed to make this a fully voluntary skill.
Involuntary Flaring and Its Purpose
While deliberate flaring is a learned skill, the nostrils also widen involuntarily for functional and expressive reasons. Physiologically, nasal flaring is an adaptive response to increase the volume of air entering the lungs when oxygen demand increases. This is observed during intense physical exertion, such as running or heavy lifting, when the body requires maximum oxygen intake.
The action is also a component of the body’s “fight-or-flight” response, where the sympathetic nervous system prepares the body for action. During moments of stress, anxiety, or excitement, the body anticipates a need for higher respiratory capacity. This causes the nostrils to dilate, minimizing airway resistance and maximizing airflow. This reflexive widening ensures efficient oxygenation during a perceived threat or high-demand situation.
Beyond its physical function, involuntary flaring serves as a non-verbal cue signaling strong emotional states. The slight, unconscious dilation communicates emotions like anger, aggression, or intense concentration. This expressive widening is a subtle but recognizable sign of heightened emotional arousal, reflecting a connection between the facial musculature and the autonomic nervous system.