To the Editor I read with interest the Viewpoint recently published in JAMA Pediatrics expressing frustration with the term functional pain to describe the common scenario of chronic pain from unidentified causes.1 However, I question the author’s recommendation to change the name to primary pain disorder.1 Just because the cause of a symptom is unknown does not mean that it has no cause; absence of proof is not proof of absence. Diagnostic delay is common in complex illnesses and not all patients have access to comprehensive diagnostic evaluations.