Menstrual cycle and menstrual pain problems and related risk factors among Japanese female workers.

Women's employment in Japan has increased substantially in recent decades, however little large scale research has been done on the impact of various types of working conditions on women's health. The aim of this study was to assess the menstrual cycle and menstrual pain problems of female workers and to investigate the factors that relate to them. The questionnaire was distributed to 8,150 women and 2,166 responded (26.6%). An anonymous self-administered questionnaire was used to get information about demographics, menstrual cycle status, the degree of menstrual pain, and employment and environmental factors. Irregular cycle menstruation was experienced in 17.1% of responded workers. We discovered the relationship between irregular menstrual cycles and stress, smell of cigarettes, age and smoking habits. Some degree of menstrual pain was experienced in 77.6% of responded workers. This study showed the relationship between menstrual pain and stress, high temperature and humidity, age, BMI, and number of births. In conclusion, we found that stress is thought to be an important factor related with menstrual cycle irregularities and menstrual pain among Japanese female workers.