Abstract:A female case with the Kleine‐Levin syndrome (KLS), which first occurred at the age of 19, was discussed in relation to the following four characteristics: 1) a female case, 2) a loss of memory and the appearance of slow waves in the pathosis, 3) the abnormal pattern of growth hormone (GH) secretion during sleep in the pathosis, and 4) a prolonged latency between the peaks of III and V in the auditory brainstem response (ABR) in both the pathosis and nonpathosis. These characteristics may suggest that there is a slight disturbance of consciousness in the pathosis, and that there is a functional disturbance in the hypothalamu