A symptom may be literally a word trapped in a body. Remember that all that children really know about their internal organs is what their parents tell them. The inside of their body is thus made up of words. Doctors are familiar with patients who complain of pains when a biological cause is clearly absent. This does not mean that the pain is false: it is exactly the same pain, perhaps even a greater one, as if it were caused by some real physical determinant.
Lacan for beginners Darian Leader and Judy Groves The Bath Press, Avon, Great Britain 1995, P51