Study aim: Determining the effect of modifying the pattern of drinking water on the severity of dysmenrrhea, the amount and variety of drugs consumed. Design: The girls who think that they consume less than 8 glasses of water per day and have early dysmenorrhea, are invited to enter the study. First, the severity of dysmenorrhea in girls will examined by using a visual scale. Individuals who choose at least 3 out of 10, will be selected. Then they will record daily water intake for at least 5 days. If they take less than 8 glasses of water each day, they will be included in the study. Settings and conduct: This research will be carried out at the Islamic Azad University of Isfahan (Khorasgan). Girls who have primary dysmenorrhea and drink less than 8 glasses of water per day will be included in the study. Participants/Inclusion and exclusion criteria: History of primary dismenorrhea drinking less than 8 glass per day(each glass contains 250 cc) Intervention groups: Samples will drink 8 to 10 glass of water every day. Main outcome variables: Reducing the consumption of pain relieves for dysmenorrhea, promote girls' health, improve their quality of life