Young woman walking in front of a yellow wall

How your menstrual cycle affects your mood

190 views 2 min to read

Experiencing mood swings in the days just before your period is common, but your menstrual cycle can affect your emotions and outlook all month long. Here’s how your feelings might shift during your cycle.

If you feel more moody, sad, angry or just plain irritated in the days before your period is due, you’re definitely not imagining it.

Nine out of 10 women say they experience some premenstrual syndrome (PMS) symptoms, and mood swings and irritability are the most common.

Researchers still aren’t sure exactly what causes PMS, but changes in and interactions between hormones and certain brain chemicals are likely to play a key role.  

But the hormones that control your menstrual cycle ebb and flow, meaning you’ll probably experience mood changes at other times of the month, too.  

Here’s how you might feel during the four different phases  of your menstrual cycle.

Phase 1: Menstruation

This phase kicks off on day one of your period,  and typically lasts between three days and one week.  Menstruation occurs when an egg hasn’t been fertilised, causing estrogen and progesterone levels to drop . Research shows it’s quite common to continue to feel a little down or experience mood swings during the first few days of your period.

Phase 2: The follicular phase

Technically, this phase also starts on day one of your period, so there’s a slight cross over with the menstruation phase.  

It begins when your hypothalamus (a region of your brain) signals to the pituitary gland (also located in your brain) to release the follicle-stimulation hormone. This leads to a surge in estrogen that thickens the lining of your uterus .

If you have a 28-day cycle, this phase typically lasts for two weeks  and once the first couple of days of your period are over, you might start to notice your energy levels increasing. 

Plus, you might feel as if your brain’s sharper, so that you can remember and recall things more easily. Your tolerance for pain might be higher, too.
Get the latest in wellbeing news
Sign up to the fortnightly wellbeing update and get the latest articles, recipes and more delivered straight to your inbox!

Phase 3: Ovulation

The shortest phase of the cycle, ovulation only lasts between 16 and 32 hours, and is when you’re most fertile.

For many women, positive emotions and feelings peak at this phase of the cycle,  perhaps thanks to the surge in luteinising hormone that’s required to trigger ovulation.

Phase 4: The luteal phase

This lasts for about 14 days  and, as those days pass, you may start to feel a little sluggish and absent-minded,  as well as irritable, sad, moody and even angry, as PMS well and truly kicks in.  

One explanation for the mood-related symptoms may be that during the luteal phase, there is a drop  in levels of serotonin, a brain chemical that’s sometimes called the “happy chemical ”. For most women, symptoms of PMS start between four and 10 days before menstruation begins.

If you experience PMS symptoms, including mood swings, and they bother you, increasing your intake of healthy fatty acids and vitamin B foods may help to turn the dial down.