night sweat [AS, niht + swaetan] , 1. sweating that occurs with a nocturnal fever, as in wasting diseases such as pulmonary tuberculosis or cancer. 2. nocturnal sweating by a woman as an effect of menopause or perimenopause. The sweating, which may be mild or profuse enough to disrupt sleep, is believed to be caused by fluctuations in estrogen levels. 3. profuse sweating at night in an environment of normal temperature. It may be associated with medications, hormonal disorders, hypoglycemia or neurologic disorders.
