Vocal Cord Dysfunction (VCD), also known as Inducible Laryngeal Obstruction (ILO), is a respiratory disorder that involves the unexpected and inappropriate closure of the vocal cords. Instead of remaining open to allow air to pass freely, the vocal cords paradoxically adduct, or close, during the breathing cycle, most often during inhalation. This sudden narrowing of the airway causes alarming symptoms that can feel like suffocating, leading many individuals to wonder if the condition is fatal.
The Mechanism of Vocal Cord Dysfunction
VCD is a functional disorder, meaning the structure of the larynx is normal, but its movement is dysfunctional and involuntary. During normal respiration, the vocal cords should abduct to create a clear pathway for air to move into the lungs. In a VCD episode, the vocal cords inappropriately adduct, causing an obstruction at the level of the voice box.
This paradoxical closure significantly limits the amount of air that can be inhaled, producing a high-pitched, noisy breathing sound called stridor. The mechanism is often described as a hyperfunctional and inappropriate laryngeal closure reflex, which can be triggered by irritants, exercise, or emotional stress. Although the sensation of being unable to breathe is intense, the condition is caused by muscle spasm, not a structural blockage.
VCD vs. Life-Threatening Airway Obstruction
Vocal Cord Dysfunction, despite its frightening symptoms, is rarely a fatal condition. The episodes are typically self-limiting, meaning the vocal cords usually relax and open spontaneously before a complete and permanent obstruction occurs. Even during a severe episode, diagnostic tests often show that the oxygen saturation levels in the blood remain normal, indicating that some air is still reaching the lungs.
A key difference is that VCD is a functional spasm, unlike true life-threatening obstructions such as severe laryngeal edema from anaphylaxis or a foreign body aspiration. Furthermore, a prolonged, severe VCD episode can potentially lead to complications, but the condition is not considered a direct cause of death.
Another significant mitigating factor is that if a person were to lose consciousness due to the reduced airflow, the vocal cords would automatically relax and open, restoring breathing. The main risk associated with VCD is not the condition itself but the panic and anxiety it induces, which can intensify the symptoms. Accurate diagnosis and management of the anxiety component are therefore important in reducing the perceived severity of the attacks.
Conditions VCD Often Mimics
VCD presents a significant diagnostic challenge because its symptoms closely resemble those of other severe respiratory conditions. The most common misdiagnosis is asthma, as both conditions cause wheezing, shortness of breath, and chest tightness. VCD is often referred to as “pseudo-asthma” because patients frequently present with symptoms refractory to standard asthma treatment.
A distinguishing feature is that the wheezing sound in VCD is typically heard when inhaling, known as stridor, whereas in asthma, the wheeze is primarily heard on exhalation. Unlike true asthma, VCD episodes do not respond to bronchodilator medications, which only work on the lower airways.
VCD can also mimic anaphylaxis, particularly when symptoms include throat tightness and respiratory distress. The risk here is that misdiagnosis leads to unnecessary and potentially harmful use of high-dose steroids or other medications intended for different conditions.
Immediate Management of a VCD Episode
The immediate management of a VCD episode focuses on using specific breathing techniques to override the involuntary spasm of the vocal cords. Controlled breathing exercises, often taught by a speech-language pathologist, are the primary intervention for an acute episode.
A common technique is the “Quick Sniff,” which involves taking a few rapid, deep sniffs through the nose, followed by a slow exhale through pursed lips, often making an “s” or “sh” sound. This action forces the vocal cords to momentarily open and helps to gain control over the breathing pattern. Learning diaphragmatic breathing, which focuses on expanding the belly rather than the chest, also helps to keep the throat muscles relaxed and prevent constriction.
Long-term management involves respiratory retraining therapy, biofeedback, and addressing underlying triggers like gastroesophageal reflux disease or anxiety.