Diarrhea (Hyperthyroidism Hiding In Plain Sight)

Diarrhea is one of those conditions that everyone can say they had at one time or another. It is like the common cold. Yet, diarrhea can be the symptom of more ominous conditions that are sometimes easily overlooked. To put it another way, we can say that some systemic diseases can masquerade as diarrhea, driving practitioners to the brink of insanity as they struggle to uncover the underlying cause of a patient’s diarrhea. While the more familiar causes like infection and bowel inflammation are easily recognized, the less common causes of diarrhea can create a dilemma for practitioner and patient alike. Hyperthyroidism is one such systemic use that sometimes can mislead and cause headaches for practitioners if they do not think of hyperthyroidism while doing their work-up of a patient’s diarrhea. Scientists have been aware of the role of hyperthyroidism as a cause of diarrhea for decades, but the exact mechanism by which it causes diarrhea remains an enigma. Speculations have been made regarding the mechanism by which hyperthyroidism causes diarrhea, such as the decreased transit time and secretory diarrhea caused by a disturbance of the electrolyte flux in the bowel wall. Hyperthyroidism is a known cause of diarrhea, but without constant vigilance, we are apt to overlook it.