Unilateral diaphragmatic paralysis in a diabetic patient: a case of trepopnea.

Dyspnea is a common presenting complaint. Trepopnea, an under-recognized form of dyspnea, is difficult breathing in only one lateral decubitus position. One cause of trepopnea is unilateral diaphragmatic paralysis, which in itself is an uncommon diagnosis. We report a unique case of a 55-year-old diabetic man who presented with trepopnea and was found to have unilateral diaphragmatic paralysis secondary to isolated diabetic phrenic neuropathy. This case highlights the importance of recognizing trepopnea as an early clinical symptom of diaphragmatic paralysis and discusses diabetic phrenic neuropathy which can occur in the absence of peripheral neuropathy.