Most interpersonal communication textbooks list the major emotions, talk about the need to be able to describe what you’re feeling, and provide a variety of terms to describe the basic or primary emotions. It’s part of emotional communication competence. Alexithymia, on the other hand, is a condition in which a person lacks the vocabulary to effectively describe his or her feelings, wants, and desires. State alexithymia is temporary and is triggered by a specific event; trait alexithymia is a personality characteristic and manifests itself often and in a wide variety of contexts. People high in alexithymia, not surprisingly, are handicapped in their ability to form and to maintain close interpersonal relationships. Take a look at Ross Buck’s article and related posts. It adds greatly to what appears in many textbooks.