Upper gastrointestinal endoscopy can, in rare cases, damage your vocal cords. The endoscope passes through the throat in close proximity to the structures that control voice production, and the mechanical pressure it exerts can injure the recurrent laryngeal nerve or dislocate the small cartilages that move the vocal folds. Most people come through the procedure with nothing worse than mild throat soreness, but the risk is real enough that case reports and clinical reviews have documented it across multiple types of endoscopic procedures.
How the Endoscope Reaches the Vocal Cords
During a standard upper gastrointestinal endoscopy, a flexible tube roughly the diameter of a finger is guided through the mouth, past the back of the throat, through the upper part of the esophagus, and into the stomach. On its way down, the scope slides past the pyriform sinuses, a pair of small pockets on either side of the larynx. The recurrent laryngeal nerve, which controls the muscles that open and close the vocal folds, runs right alongside this area. The arytenoid cartilages, tiny structures that pivot the vocal cords into position for speaking and breathing, sit just next to the path the scope travels.
This tight geography is the core of the problem. The endoscopic tip can press against the recurrent laryngeal nerve or bump the arytenoid cartilages as it passes through the pyriform sinus. The gag reflex, which most patients experience at least briefly during insertion, can compound this by causing forceful muscle contractions that push the scope harder against those delicate structures.1Clinical Endoscopy. Two Cases of Vocal Cord Paralysis Complicated by Upper Gastrointestinal Endoscopy Most gastrointestinal endoscopists are focused on what they see below the vocal cords and may not routinely inspect the laryngopharyngeal area, which means subtle injuries in this zone can go unnoticed during the procedure itself.2Europe PMC. Observable Laryngopharyngeal Lesions during the Upper Gastrointestinal Endoscopy
Types of Injury That Can Happen
The injuries fall into a few categories, and they range from temporary irritation to problems that take months to resolve.
- Nerve compression: Pressure from the scope tip on the recurrent laryngeal nerve can cause a condition called neuropraxia, which is essentially a bruise to the nerve. The nerve stops conducting signals properly, and the vocal cord on the affected side becomes weak or paralyzed. This can happen on one side or, in rarer therapeutic procedures like esophageal stent placement, on both sides.3PubMed Central. Bilateral vocal cord paralysis after endoscopic placement of fully covered self-expandable metal stent for palliative treatment of malignant proximal esophageal obstruction: two case reports
- Arytenoid dislocation: The arytenoid cartilages can be knocked out of their normal position by mechanical force from the passing scope. When one of these cartilages is dislocated, it cannot pivot the vocal cord properly, leading to hoarseness and sometimes airway problems.4Thieme Connect (Endoscopy). Arytenoid dislocation following upper gastrointestinal endoscopy
- Inflammation and swelling: Even without a specific nerve or cartilage injury, the mechanical passage of the scope can inflame the tissues around the larynx, causing temporary hoarseness or vocal fatigue.
Therapeutic endoscopic procedures carry higher risk than a simple diagnostic scope. When the endoscopist is dilating a narrowed esophagus or placing a stent, the instruments are larger, the procedure takes longer, and more force is involved. In cases of esophageal stent placement, the stent itself can gradually compress the posterior larynx as it expands in the days after the procedure, leading to progressive voice and breathing problems that worsen over time rather than appearing immediately.3PubMed Central. Bilateral vocal cord paralysis after endoscopic placement of fully covered self-expandable metal stent for palliative treatment of malignant proximal esophageal obstruction: two case reports
Laryngospasm During the Procedure
A separate concern is laryngospasm, a sudden involuntary closure of the vocal cords that can happen when the scope contacts the throat. This is not an injury in the usual sense but rather a reflexive clamping shut of the airway. It typically resolves within seconds to minutes, but it can be alarming and occasionally requires intervention.
A large study of anesthesia-related complications found that esophagoscopy carried one of the highest rates of laryngospasm among all procedures, with more than 50 episodes per 1,000 patients. Oral endoscopy more broadly had rates exceeding 25 per 1,000.5PubMed. Laryngospasm during anaesthesia. A computer-aided incidence study in 136,929 patients These numbers reflect procedures done under anesthesia, which involves additional airway manipulation. For a standard sedated endoscopy without general anesthesia, the rate is likely lower, but the reflex can still occur during the initial passage of the scope.
What Symptoms Should Concern You
Some throat discomfort after an endoscopy is completely normal. Most people experience a scratchy or sore throat for a day or two, and that clears up on its own. The symptoms that should prompt you to contact your doctor are different in character and duration.
Hoarseness that persists beyond a few days is the most common warning sign of a vocal cord injury. Breathiness, where your voice sounds airy because the vocal cords cannot close fully, is another. You might notice that your cough feels weak or ineffective, since closing the vocal cords forcefully is part of how you generate a strong cough. In a published case involving endoscopic dilation of an esophageal stricture, a patient developed persistent hoarseness that had not improved four months later. An ENT examination revealed an immobile vocal cord on one side, decreased maximum phonatory time, poor cough, and a breathy quality to the voice. The working vocal cord on the opposite side was overcompensating by contracting more forcefully than normal to try to close the gap.6Gastroenterology. Hoarseness of Voice After Endoscopic Dilation of an Esophageal Stricture
If hoarseness lasts more than two weeks after an endoscopy, you should see an ear, nose, and throat specialist. A flexible laryngoscopy, a quick in-office examination using a thin camera through the nose, can determine whether the vocal cords are moving normally. Catching a vocal cord injury early matters because some treatments work best when started sooner rather than later.
Who Faces Higher Risk
The evidence on risk factors comes largely from studies of intubation-related vocal cord paralysis rather than endoscopy specifically, but the underlying mechanics are similar enough that the risk factors overlap. Age is the most consistent predictor. People over 50 face roughly three to four times the risk of vocal cord paralysis after airway procedures compared to younger adults.7PubMed. Age and comorbidity as risk factors for vocal cord paralysis associated with tracheal intubation The laryngeal tissues become less resilient with age, and the joints connecting the arytenoid cartilages stiffen, making them more vulnerable to dislocation or compression injury.8PubMed Central. Vocal Cord Paralysis after Tracheal Intubation: An Overview of the Etiology and Associated Risk Factors
Diabetes and hypertension also increase the risk. The same study found that diabetes raised the odds by about two and a half times, and hypertension roughly doubled them.7PubMed. Age and comorbidity as risk factors for vocal cord paralysis associated with tracheal intubation Both conditions affect blood flow in small vessels, and the recurrent laryngeal nerve depends on a good blood supply to recover from even minor compression. A nerve that is already compromised by diabetes-related damage may not tolerate the added stress of mechanical pressure the way a healthy nerve would.
Lower body mass index has also been flagged as a potential risk factor, since people with less tissue padding around the larynx may have arytenoid cartilages and muscles that are more exposed to direct mechanical force.8PubMed Central. Vocal Cord Paralysis after Tracheal Intubation: An Overview of the Etiology and Associated Risk Factors That said, the evidence for this is thinner than for age and diabetes.
Does the Throat-Numbing Spray Make Things Worse
Before many endoscopies, a topical anesthetic (usually lidocaine) is sprayed into the throat to suppress the gag reflex. A reasonable concern is whether this numbing spray itself affects how the vocal cords work or contributes to injury.
Research on this question gives a reassuringly clear answer on one front: topical anesthesia applied to the larynx and pharynx does not affect vocal fold motion. A study specifically designed to test this found no difference in vocal cord movement before and after the spray was applied.9PubMed. The effect of topical anesthesia on vocal fold motion Your vocal cords keep moving normally even when the surrounding tissue is numb.
The picture is slightly more complicated when it comes to overall airway function. Topical lidocaine can temporarily increase airway resistance, and fiberoptic examinations of patients who responded most strongly to this effect showed some inspiratory laryngeal collapse. The researchers interpreted this as a form of laryngeal dysfunction caused by the numbed tissue not maintaining its usual tone.10PubMed. Topical upper airway anaesthesia with lidocaine increases airway resistance by impairing glottic function This is a transient effect that resolves as the anesthetic wears off, and it does not cause lasting vocal cord damage. On the positive side, topical lidocaine dampens protective airway reflexes, which may actually reduce the intensity of laryngospasm during the procedure.11PubMed. Does topical anesthesia using aerosolized lidocaine inhibit the superior laryngeal nerve reflex? So the numbing spray is a trade-off, but it is not a direct cause of vocal cord injury.
What Happens If a Vocal Cord Is Paralyzed
The outlook depends on whether one or both vocal cords are affected, and on the type and severity of the nerve injury.
One-sided vocal cord paralysis is more common and less dangerous. You will sound hoarse and may have a breathy voice, but your airway stays open because one cord is still moving. Many cases of neuropraxia, where the nerve is bruised but not severed, recover spontaneously over weeks to months as the nerve heals. If the nerve injury is more severe, the paralysis may be permanent, but even then there are effective treatments. Surgical procedures can reposition the paralyzed cord or inject material to bulk it up so the working cord can close against it more effectively.
Two-sided vocal cord paralysis is more serious because both cords may sit in a near-closed position, restricting the airway. This is much rarer after standard endoscopy and is more associated with stent placement or complex therapeutic procedures. When it does happen, surgical intervention is usually necessary. One approach, arytenoidectomy combined with posterior cordectomy, involves removing or reshaping one of the arytenoid cartilages and cutting part of the vocal cord to widen the airway. In a study of 30 patients treated this way for bilateral paralysis, 96 percent were able to breathe normally and return to daily activities within 60 days.12PubMed. Treatment of bilateral vocal cord paralysis following permanent recurrent laryngeal nerve injury
For one-sided paralysis that causes breathing difficulty, a newer approach called endoscopic arytenoid abduction lateropexy pulls the paralyzed cord to the side to open the airway. A study of patients treated this way found significant improvements in breathing, voice quality scores, and quality of life, and the improved breathing did not come at the cost of a worse voice.13PubMed. Functional outcomes of endoscopic arytenoid abduction lateropexy for unilateral vocal cord paralysis with dyspnea These surgical options mean that even permanent vocal cord paralysis after endoscopy is not a dead end, though obviously everyone would prefer to avoid it in the first place.
Endoscopy in Children
Parents bringing a child in for an upper endoscopy sometimes worry about this risk more acutely, since children’s airways are smaller and the proportional size of the endoscope relative to the throat is larger. A large review of 616 pediatric endoscopic procedures found an overall complication rate of 1.6 percent, though that figure covers all complications, not vocal cord injuries specifically.14PubMed Central. Pediatric endoscopy: a review of 616 cases The laryngeal tissues in children are more pliable and resilient than in older adults, which is one reason why intubation-related vocal cord paralysis is essentially unreported in people under 20.8PubMed Central. Vocal Cord Paralysis after Tracheal Intubation: An Overview of the Etiology and Associated Risk Factors The risk is not zero, but it appears to be lower than in older adults.
Children are, however, more prone to laryngospasm during airway procedures, particularly those under three months of age or those with active respiratory infections or asthma.5PubMed. Laryngospasm during anaesthesia. A computer-aided incidence study in 136,929 patients This is usually managed successfully in the moment by the anesthesia team, but it is worth mentioning to your child’s doctors if your child has a current cold or respiratory symptoms so the timing of the procedure can be reconsidered.
The Informed Consent Conversation
Vocal cord injury is one of those risks that sits in an uncomfortable zone: too rare for most patients to ever experience, but serious enough when it does happen that it deserves mention. A review of closed malpractice claims related to vocal cord injuries from airway procedures emphasized that a detailed discussion of risks before the procedure, careful documentation of that discussion, and prompt referral to a specialist if voice problems develop afterward are all critical.15PubMed. A closed claims analysis of vocal cord injuries related to endotracheal intubation between 2004 and 2015
If you rely on your voice professionally (singing, teaching, broadcasting, trial law), it is worth raising this specific concern before your procedure. The endoscopy team may not think to mention vocal cord risk unless asked, because for most patients the chance is very low and the sore throat resolves quickly. But for someone whose livelihood depends on their voice, even a temporary injury has different stakes. Your doctor might adjust the sedation approach, choose a smaller-diameter scope, or schedule a follow-up voice check after the procedure as a precaution.
When Standard Endoscopy Gets Confused with Laryngeal Procedures
Some of the alarm around endoscopy and vocal cords comes from confusion between different types of scopes. A standard upper gastrointestinal endoscopy passes the vocal cords on its way to the esophagus and stomach; it does not target the vocal cords themselves. By contrast, laryngoscopy is a procedure specifically designed to examine or treat the vocal cords, and flexible endoscopic procedures on the larynx carry their own distinct set of risks, including inflammatory reactions at injection sites when materials are being placed into the vocal folds.16PubMed Central. Voice outcome measures after flexible endoscopic injection laryngoplasty
If you have been told you need an endoscopy and are worried about your voice, the first thing to clarify is exactly what kind of endoscopy is being planned. A diagnostic upper GI endoscopy to check for ulcers or reflux damage is a quick procedure with a very low risk to the vocal cords. An endoscopic dilation of a narrowed esophagus involves more mechanical force and carries a somewhat higher risk. And a laryngeal endoscopy is a fundamentally different procedure with its own risk profile. Knowing which one you are scheduled for makes the risk conversation much more concrete.