Dear men, the next time you joke that a woman is being cranky because she is on her period, know this: periods don't make women moody.
The real enemy here is PMS, or premenstrual syndrome as it is better known. Sound terrifying? Oh, believe us, it is.
The first thing to clear up (excuse the pun) is that PMS isn't the same thing as a period. PMS involves a series of physical and emotional symptoms including irritability, stress, upset, stomach cramping and the inability to sleep.
It is estimated that 50-80% of women have experienced PMS in their lifetime.
Although the exact causes of PMS are unknown, it is believed to be related to the flux in hormones (oestrogen and progesterone) during the luteal phase of the menstrual cycle (from ovulation to the beginning of menstruation).
Although most of the action during the menstrual cycle occurs in the reproductive organs, the change in hormones greatly affects the brain.
According to the ASAP Science video above: "During PMS, the amygdala in the brain, which controls emotion, increases its activity, we also see lower levels of the feel-good chemical seratonin and the neuro-transmitter gaba which has anti-anxiety effects, meaning stress and anxiety run high."
Sounds fun, huh?
Thankfully, as soon as menstruation begins, the cocktail of hormones decreases considerably, meaning all crazy moodiness ebbs away. But don't worry, it'll all be back again the following month.
[H/T Laughing Squid]