Final answer:
Vocal cord nodules typically result from chronic or excessive strain on the vocal cords, often caused by activities like yelling, singing, or prolonged speaking.
Step-by-step explanation:
The usual cause of a vocal cord nodule is chronic or excessive strain on the vocal cords. This can result from activities such as yelling, singing, or speaking in an unhealthy manner over long periods of time. The true vocal cords, located in the larynx, are lined with a protective epithelium that can be susceptible to damage. Overuse of the vocal cords can lead to inflammation and the development of nodules, which are small, benign, callous-like growths. These nodules can cause symptoms such as hoarseness or a breathy voice.
Vocal cord nodules are similar to calluses that form on the skin and are often referred to as singer's or screamer's nodules due to their association with professions that require frequent vocal use. The stratified squamous epithelium lining the superior portion of the larynx is designed to withstand some mechanical stress, but persistent strain can exceed its capacity for protection, resulting in nodules.