If in the menstruation, in the first 1-2 days of light blood watery menstruation, usually there is no problem, but if in the menstruation lasts for a few days, has been a little bit of light blood watery menstruation is abnormal, consider that it is caused by menstrual irregularities. Normal menstruation lasts for 3-5 days, up to 7 days, and the amount of menstruation is around 30-80mL, too much or too little bleeding is not normal. Causes of menstrual disorders are more, any cause of hypothalamic-pituitary-gonadal axis function abnormalities, can cause menstrual irregularities, such as taking hormonal drugs, have pelvic inflammatory disease, ovarian cysts, frequent late nights, emotional instability, excessive stress, anxiety, etc. can also cause the impact of normal menstruation, it is recommended that it is best to go to the hospital for examination, to find the cause of the standardized treatment.