A conceptual organization of voice disorders
Upon diagnosing a voice problem, I subdivide causes of hoarseness into two primary categories. I think of these broad categories in terms of what causes the vocal cord dysfunction and so I name them functional hoarseness and structural hoarseness. This categorization is based upon the perceived cause of the hoarseness and it helps in directing the type of treatment for the problem.
By functional, I mean that the problem has arisen from how the voice is used. The vocal behavior or pattern of use causes the problem. An example would be the person who talks so much that the voice becomes hoarse. The function (overuse) caused a change in the structure, usually swelling in the middle of the vocal cord, which causes an air leak around the swelling and stiff portion, and thus hoarseness.
A structural hoarseness problem is one in which the vocal cord structure changed as the primary etiology. For example, a smoker over many years of exposing their vocal cords to tobacco ingredients and heat, may develop a cancer. While smoking is a behavior, it is not a vocal behavior. This cancerous growth or bump on the vocal cords has nothing to do with how much or little the person makes the vocal cords vibrate. As the bump grows, it changes the weight and stiffness on one vocal cord and causes perhaps both air leak around the bump (huskiness) as well as two separate pitches (roughness).
This distinction of functional and structural is arbitrary and perhaps even wrong at times. Changes in function sometimes alter the structure and changes in structure may alter the function, so they are highly inter-related and telling which came first might be difficult in some cases. Nonetheless, categorization of voice problems, based in principle on whether the vocal behavior plays a role in the onset of the problem, will prove helpful not only in diagnosing, but especially in treating, the problem.
Functional
Functional voice disorders can be broken down into three broad subcategories:
- mucosal
- muscular
- non-organic
Mucosal disorders develop predominantly in vocal overdoers. Vocal overuse abrades the surface, that is, the mucosa. The mucosa reacts, so mucosal disorders develop typically from overuse. Muscular disorders develop mostly in vocal underdoers. Lack of use leads to muscle atrophy. People who do not talk much tend to have thinner vocal cords. Non-organic disorders are issues with vocal technique. These problems are often associated with excess tension in the vocal cords. To elaborate on the classification:
- mucosal - overdoer
- muscular - underdoer
- non-organic - does not do it correctly (Improper doer)
Structural
Structural disorders can be broken down into a number of categories. Something outside or intrinsic to the larynx causes the problem, but the problem is not related to vocal behavior. They are not related to how the vocal cords are used. I utilize the following partial list as a starting point:
- congenital
- inflammatory
- mucous
- neurologic
- trauma
- tumor
- unusual (endocrine, hematologic, foreign body)