Sighing dyspnea is of rather common occurrence, is never due to organic disease, and is in itself of trivial prognostic importance. However, it is not infrequently mistaken for asthma or for serious cardiac or other organic disease. It is one of the most common causes of spontaneous tetany and should be considered a possible etiologic factor in all cases of tetany. Relief from the symptoms depends entirely upon a clear and comprehensive explanation of the condition to the patient.