An indirect laryngoscopy is a procedure that allows doctors to view the larynx, or voice box, close up without a direct line of sight. It helps diagnose irregularities of the larynx and throat.

The larynx, also known as the voice box, is positioned on top of the trachea, or windpipe.

Doctors may need to examine the larynx for several reasons, such as to help diagnose an injury or medical condition. Different types of laryngoscopies are available. An indirect laryngoscopy helps the doctor see the vocal cords close up using a mirror or video screen.

This article discusses the indirect laryngoscopy procedure, including preparation, what to expect, results, risks, and frequently asked questions.

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An indirect laryngoscopy provides an indirect view of the larynx and nearby structures. This means a doctor views the airway structures without a direct line of sight. Instead, it is via a reflection in a mirror.

Using a laryngeal mirror is low tech and the simplest way to view the larynx and throat.

There is no specific preparation for an indirect laryngoscopy.

However, doctors tend to perform the procedure with a local anesthetic medication. Most of the time, people remain fully awake.

It is also important to follow a doctor’s instructions before an indirect laryngoscopy.

An indirect laryngoscopy usually takes 5–10 minutes in a doctor’s office. The exact procedure may vary slightly depending on the type of scope the doctor uses. Typically, individuals should expect to sit up in a chair while the doctor administers numbing medication through a spray to the back of the throat.

Once the numbing takes effect, the doctor may cover the tongue with gauze and hold it to prevent it from blocking the view. The doctor inserts a special small mirror into the throat and shines a light into the mouth to direct light parallel to the field of vision.

Individuals may receive instructions to say a word or try to make a certain sound. This helps the doctor see the activity of the vocal cords.

Once the doctor views the larynx and throat, they are able to tell an individual their findings as soon as they complete the examination. For instance, after viewing the structures, the doctor may detect an injury.

However, in some cases, the doctor may take additional tests, such as a biopsy, to make a diagnosis of an irregularity found during the exam. The doctor will explain the need for follow-up and when to expect the results from further testing, which can take up to several days.

Indirect laryngoscopy is generally a safe procedure. Typically, the doctor performs an indirect laryngoscopy using a local numbing medication, not general anesthesia or sedation.

Possible effects of a mirror laryngoscopy include:

  • injury to the mucosa — the soft tissue in the mouth — which may cause bleeding
  • laryngospasm — vocal cord spasm — and airway compromise
  • gagging
  • coughing
  • vomiting

The following are answers to some common questions about indirect laryngoscopy.

What is an indirect laryngoscopy?

An indirect laryngoscopy is a procedure that uses a mirror placed in the back of the throat with the glass side down. The doctor moves the mirror upward toward the roof of the mouth. This allows for viewing the larynx through the image in the mirror.

What is the difference between a direct and indirect laryngoscopy?

A direct laryngoscope involves the doctor inserting a scope into the mouth to see the larynx directly in a straight line. With an indirect laryngoscopy, the doctors view the image in a mirror’s reflection.

Why do we do indirect laryngoscopy?

Doctors perform an indirect laryngoscope to examine the larynx and structures in the throat. It helps identify growths, both benign and cancerous. It is also useful for people who have:

Is an indirect laryngoscopy painful?

Before an indirect laryngoscopy, doctors often administer a numbing spray to decrease discomfort and gagging. This may make the exam easier to tolerate.

An indirect laryngoscopy involves using a mirror to view the larynx without a direct line of sight. Doctors perform the procedure to examine the larynx and surrounding structures.

People do not usually need to prepare in advance but should follow any instructions given to them by their doctor.

The procedure takes 5–10 minutes, and doctors will use numbing medication on the back of the throat to decrease any discomfort a person may experience. The doctor can tell an individual their findings right away. However, they may suggest further testing, such as a biopsy, depending on what they see.

Risks are minimal but may include bleeding, infection, and gagging during the procedure.