Indirect laryngoscopy uses a small mirror held at the back of your throat. The doctor shines a light on the mirror to view the throat area. This simple and fast procedure is most often done in the doctor's office while you are awake. A medicine to numb the back of your throat may be used.
Fiberoptic laryngoscopy uses a small flexible telescope, which is passed through your nose and into your throat. This is the most common way that the voice box is examined. You are awake for the procedure. Numbing medicine will be sprayed in your nose. This procedure typically takes less than 1 minute.
Direct laryngoscopy uses a tube called a laryngoscope, which is placed in the back of your throat. The tube may be flexible or stiff. This procedure allows the doctor to see deeper in the throat and to remove a foreign object or sample of tissue for a biopsy. It is done in a hospital or medical center under general anesthesia, meaning you will be asleep and pain-free.
How to prepare for the test
How to prepare for the test depends on which type of laryngoscopy is done. If it is being done under general anesthesia, you may be told not to drink or eat anything for several hours before the test.
How the test will feel
How the test will feel depends on which type of laryngoscopy is done.
Indirect laryngoscopy using a mirror can cause gagging. For this reason it is not often used in children under age 6 - 7 or those who gag easily.
Fiberoptic laryngoscopy can be done in children. It may cause a feeling of pressure and a feeling like you are going to sneeze.
Why the test is performed
This test can help your doctor diagnose many different conditions involving the throat and voice box. Your health care provider may recommend this test if you have:
Bad breath that does not go away
Breathing problems, including noisy breathing (stridor)
Coughing up blood
Ear pain that does not go away
Feeling that something is stuck in your throat
Long-term upper respiratory problem in a smoker
Mass in the head or neck area with signs of cancer
Throat pain that does not go away
Voice problems that last more than 3 weeks, including hoarseness, weak voice, raspy voice, or no voice
A direct laryngoscopy may also be used to:
Remove a sample of tissue in the throat for closer examination under a microscope (biopsy)
Remove an object that is blocking the airway, for example, if a child swallowed a marble or coin
A normal result means the throat, voice box, and vocal cords appear normal.
What abnormal results mean
Abnormal results may be due to:
Acid reflux (GERD), which can cause redness and swelling of the vocal cords
Cancer of the throat or voice box
Nodules on the vocal cords
Polyps (benign lumps) on the voice box
Inflammation in the throat
Thinning of the muscle and tissue in the voice box (presbylaryngis)
What the risks are
Laryngoscopy is considered a relatively safe procedure. Risks depend on the specific procedure, but may include:
Allergic reaction to anesthesia, including breathing and heart problems
Spasm of the vocal cords, which causes breathing problems
Ulcers in the lining of the mouth/throat
Injury to the tongue or lips
Indirect mirror laryngoscopy should NOT be done:
In infants or very young children
If you have acute epiglottis, an infection or swelling of the flap of tissue in front of the voice box
If you cannot open your mouth very wide
Schwartz SR, Cohen SM, Dailey SH, et al. Clinical practice guidelines: hoarseness (dysphonia). Otolaryngol Head Neck Surg. 2009;141:S1-S31.
Fowler C, Dumas C. Indirect mirror laryngoscopy. In: Pfenninger JL, ed. Pfenninger and Fowler's Procedures for Primary Care. 3rd ed. Philadelphia, Pa: Mosby Elsevier; 2010:chap 79.
Courey MS. Complications of laryngoscopy. In: Eisele DW, Smith RV, eds. Complications in Head and Neck Surgery. 2nd ed. Philadelphia, Pa: Mosby Elsevier; 2008:chap 30.
David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc., Seth Schwartz, MD, MPH, Otolaryngologist, Virginia Mason Medical Center, Seattle, Washington.