title: The lunar cycle: effects of full moon on renal colic.
abstract: OBJECTIVE
  To evaluate renal colic frequency in different seasons and around full moon.
  
  
  METHODS
  A total of 1481 patients with renal colic were studied retrospectively addressing days of a month both in solar and lunar calendar.
  
  
  RESULTS
  The mean age of the patients was 57 ± 13 years. Total admissions in summer was 613; of which 288 (41%), 199 (39%), and 126 (43%) were in years 2002, 2003, and 2004, respectively. The highest frequencies in solar calendar were on days 2 (56), 20 (63), and 27 (59) and the lowest were on days 6 (36), 22 (38), 26 (34), and 31 (31). We did not find any statistically significant association according to solar calendar (P = .3). In lunar calendar, most of the admissions were on day 15 (69) and the lowest rates were on days 1 (25) and 30 (26), which was statistically significant (P = .04).
  
  
  CONCLUSIONS
  Renal colic frequency is not correlated with solar calendar, but its highest frequency in lunar calendar is in the middle of the month period. Although we found a correlation between full moon effect and renal tide, but this is a new window for further studies.
authors.affiliation: Department of Urology, Shohada-e-Tajrish Hospital, Tehran, Iran.
authors.forename: Hojjat
authors.initials: H
authors.lastname: Molaee Govarchin Ghalae
authors.forename: Samad
authors.initials: S
authors.lastname: Zare
authors.forename: Maryam
authors.initials: M
authors.lastname: Choopanloo
authors.forename: Roya
authors.initials: R
authors.lastname: Rahimian
mesh_terms: D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016081:Moon; D056844:Renal Colic / Q000453:epidemiology*; D012621:Seasons