A large swelling on the vocal cord that typically occurs unilaterally—that is, without a similar swelling on the opposite cord. The term vocal polyp is somewhat imprecise, but vocal polyps can be distinguished from a similar kind of swelling, vocal nodules, in at least two ways: 1) polyps tend to be larger than nodules; 2) polyps occur unilaterally or are markedly larger than an injury of the opposite vocal cord, whereas nodules occur in pairs and are usually similar in size. Both vocal polyps and nodules are caused at least in part by vibratory trauma, due to vocal overuse that is acute (with polyps) or chronic.
A vocal polyp disrupts the voice’s clarity and other capabilities by interfering with accurate approximation of the vocal cords during phonation. A polyp may also add mass to the vocal cord, thereby dropping the pitch range available to the voice. Polyps may be referred to as hemorrhagic, pedunculated, and so forth.