FRIDAY, June 13 (HealthDay News) -- Having delayed sleep phase syndrome (DSPS) appears to be linked to irregular menstrual cycles and increased premenstrual symptoms in women, according to a new report.
DSPS occurs when your internal clock is naturally out of sync with real time, so that staying up late and having difficulty waking early is your norm. It is unlike such conditions as jet lag, because external factors (time zone change, noise, light) do not cause your internal clock to desynchronize.
