Along with other less-than-desirable side effects of your period, which include eating literally everything in sight and enduring the uncomfortable hum of stomach cramps, is the inevitable bloating.
During the four-to-seven days of your period (depending on how your body works), the bloat arrives and, with it, comes an increased desire to wear pyjama bottoms 98% of the time. But if you’ve ever wondered why bloating occurs during your time of the month, read on.
As Dr Penelope Law, Consultant Obstetrician and Gynaecologist at HCA UK’s The Portland Hospital, explains: “The uterus contracts daily in a mild, almost imperceptible manner.
“As you get closer to your period, these oscillating waves – usually from the fundus (the upper end of the uterus closer to the belly button) work their way down to the cervix – with a frequency of about every 40 minutes. During your period these are more intense – they originate from the lining of the uterus, called the endometrium, and are responsible for the pain some women feel,” Dr Penelope told.
Although menstrual bloating is linked to these ‘contractions’, the expert explained how it’s actually your digestive system, and not your reproductive system, that causes the swelling of your lower abdomen during your monthly bleed. And to know why your period is painful during winter read Reason Why Period Pain Is Often Worse In Winter
“During menstruation, the bowel works more slowly because the increased contractions, ‘waves’, of the uterus have an impact on how quickly food moves through the digestive system, known as peristalsis,” Dr Penelope said.
“This leads to the familiar swollen feeling many women experience whilst on their periods and can also be linked to why you can feel more constipated during menstruation.”
Of course, there may be other contributing factors to the cause of bloating on your period, like water retention. As explained on Medical News Today, this is linked to “changes in levels of the sex hormones progesterone and oestrogen.
“About a week before a woman’s period starts levels of the hormone progesterone fall. Research suggests that changes in progesterone and oestrogen levels cause the body to retain more water and salt. The body’s cells become swollen with water, causing the feeling of bloating,” the medical site reads.
So now you know: you’re bloated on your period due to a mix of excess water and full bowels. Delightful.