The vocal cords or vocal folds are the part of the upper airway (larynx) that vibrate to form sound. It is commonly referred to as the voice box. By tightening and loosening these membranous folds, the flow of air is manipulated to produce the voice which is later formed into distinct sounds by the lips, tongue and other parts of the mouth (articulation). Without the vocal cords functioning properly, the voice is hoarse or just a whisper. When the parts of the mouth responsible for articulation is affected, the speech is slurred.
What are vocal cord nodules or polyps?
Vocal nodules or polyps are growths of tissue projecting from the membranous vocal folds / vocal cords. Other terms also used for vocal nodules are vocal fold or voice box nodules / polyps. Commonly it is known as singer’s nodules or screamer’s nodules. These growths are benign.
Although the term polyp and nodule are used synonymously, there is a differentiation between the reactive nodule and polyp. Nodules tend to occur on both sides (bilaterally) towards the medial surface of the fold while polyps tend to occur on one side (unilaterally) towards the free edge of the fold towards the inferior or superior borders. A nodule is more like a focal point of thickened tissue while polyps tend to be actual outgrowths. For the purpose of this article, nodules and polyps will be discussed collectively.
Size, Shape and Structure of Nodules/Polyps
Like a benign growth elsewhere in the body, nodules/polyps may vary in size but is rarely greater than just a few millimeters at most. Typically these growths are smooth and rounded. The base of the growth may be attached to the membrane without a stalk (sessile) or with a stalk (pedunculated).
The nodule/polyp is covered by squamous epithelium which can be keratinized or is an overgrowth of normal cells or slightly abnormal cells. However, this is not a cancerous growth. The inner core is gelatinous and vascularized. In some cases, two opposing growths (usually nodules) may press and rub against each other and cause ulceration of the tissue (contact ulcers).
Causes of Vocal Cord Nodules and Polyps
In both nodules and polyps, trauma and strain to the vocal cords have been implicated as the most significant cause. Other factors such as cigarette smoking may also be a possible cause. However, nodules and polyps do not always occur with overuse of the voice or trauma. Neither does it occur in every cigarette smoker. The exact cause is therefore sometimes unknown.
- Nodules tend to occur in those people who use their voices excessively especially for speaking loudly, shouting or screaming over long periods of time or repeatedly.
- Polyps tend to rise with short periods of severe trauma (acute injury) like very loud yelling but may arise in the same circumstances as nodules. Periods of excessive and very hard coughing may also be a cause.
The etiology often means that these conditions tend to be seen more frequently in certain occupations like teachers, lecturers, professional singers, disc jockeys and drill instructors. It can also occur after a social or sporting event where excessive shouting and yelling is part of the activity.
Using an unnaturally low-pitched voice for a long period, irrespective of the volume, has also been implicated as a cause of both vocal nodules and polyps.
Signs and Symptoms
The main symptoms include a hoarse voice or whispery voice. This persistent change in the voice causes a person to seek medical attention. However, in some cases, it is mistaken for laryngitis and after a short period of rest, the voice improves only for the person to return to their previous habits and the symptoms recur. If the causative behavior is not discontinued even for short periods, the hoarseness tends to get progressively worse.
Sometimes the symptoms may not be as obvious and only a general change in the voice quality is noted without pronounced hoarseness or a whispery tone. Tobacco users may sometimes attribute this to the “smoker’s voice” but it should be investigated further. Greater effort may be required to produce vocal sounds. Other terms used to describe vocal changes include ‘raspy’, ‘rough’ or ‘scratchy’. These vocal changes are known broadly as dysphonia which is a difficulty in creating sound. This includes difficulty maintaining pitch or initiating phonation. It should not be confused with slurred speech and related problems with articulation known as dysarthria – this is a problem with the nerves and/or muscles of responsible for speech.
Pain and Discomfort
Sensations may range from neck pain, throat pain radiating to the ear or a discomfort in the throat described as a lump in the throat feeling. The latter is often associated with globus hystericus if a nodule or polyp is not identified. Therefore investigation by an otolaryngologist is crucial to avoid a misdiagnosis. Many patients with a vocal cord nodule/polyp will not experience any sensation and only the change in voice is noticed.
The severity of other symptoms may vary. Some patients may report fatigue often due to forcing phonation. Depression may sometimes be seen as a result of occupational impairment – singers who cannot maintain vocal quality or pitch and so on. Misdiagnosis and a progression of symptoms often proves frustrating to patients. Other than these associated symptoms, vocal cord nodules or polyps may go by unnoticed for long periods of time until the first vocal changes or pain and discomfort appears.