Changes in triiodothyronine mark severe pain syndrome: a case report.

Non-thyroidal illness is classically associated with a low total triiodothyronine (T3) level. Episodes of severe recurrent dental pain unassociated with fever or systemic infection in a patient was marked 2 to 3 weeks later by low T3 levels (56 ng/ml). Other thyroid and metabolic tests were normal. T3 levels returned to normal on resolution of pain. Recurrence of a transient, mild episode of pain was not associated with a low T3 2 weeks after its onset. We suggest that T3 levels may be markers for severe pain and suffering or disturbances responsible for pain and suffering in patients receiving analgesics.