The "gender sleep gap" is a phenomenon that occurs when women are more tired than men, according to Dr. Alex Dimitriu, a double board-certified psychiatry and sleep medicine doctor. The gap in sleep quality, disruptions, and insomnia can be attributed to biological and social factors such as hormonal fluctuations throughout the life cycle, menstruation, pregnancy, and menopause. However, women actually need more sleep than the recommended seven to nine hours per night. The study also revealed that 57% of women woke up in an average mood three points lower than men's.