nocturia

the passage of urine at night. In the absence of a high fluid intake, sleep is not normally interrupted by the need to pass urine. Nocturia usually occurs in elderly men or women. In younger men or women, less urine is made at night than during the day, but this rhythm is lost with age in both sexes. Men may have additional problems arising from benign prostatic hyperplasia ( see PROSTATE GLAND ), but transurethral resection of the prostate often does not reduce nocturia.