For many, premenstrual symptoms can make the lead-up to periods a dreaded time of the month. Whether you feel bloated, moody, tired or experience painful cramps, it turns out that there’s a reason! 

Premenstrual syndrome (PMS) comes with a range of different symptoms that are different from period pain. PMS symptoms typically include weight gain, bloating, irritability and fatigue, while period pain is typically pain in the lower abdomen. PMS also occurs a week or two before your period, while period pain will typically occur in the first few days of menstruation¹. While it can feel like one big process, they are two unique elements of your cycle¹. 

Learning more about the difference between period pain and PMS symptoms can help you learn what to do for each. Let’s take a closer look. 

What is PMS? 

PMS is short for premenstrual syndrome. It’s the name for symptoms some women experience in the one to two weeks leading up to the menstrual period². Roughly 8 in 100 women will experience PMS symptoms each month³.  

You may have heard people refer to the mood swings leading up to a period as PMSing, but physical and mental symptoms can also include²:

• Feeling emotional
• Experiencing fatigue or trouble sleeping
• Bloating and/or cramping
• Breast tenderness
• Headaches
• Skin spots or breakouts
• Greasy hair
• Changes in appetite and food cravings
• Trouble concentrating4
• Less motivation4
• Changes in sex drive4

How many days before a period are PMS symptoms?

So, when does PMS start? PMS symptoms are typically experienced in the one to two weeks leading up to the start of a period. This can vary from month to month, and from woman to woman, with some people who menstruate experiencing no symptoms or some experiencing more severe side effects. 

Science doesn’t fully explain or know what causes PMS exactly, but it’s generally linked to the changes in our hormones². Knowing what symptoms you experience can help you be prepared when that time of the month approaches.

Common Premenstrual Syndrome symptoms 

While many PMS and menstrual cycle symptoms will overlap, learning the difference between them can help you better adjust to your cycle. Whether you’re experiencing PMS bloating or mild anxiety,, here are some key symptoms to keep an eye out for. 

PMS bloating

In the week before your period, you may experience some discomfort or bloating. This is likely due to the fluctuating hormones that cause your body to retain more water than usual⁵. 

If you do tend to feel a bit bloated before your period there are a few things you can try to reduce your discomfort. 

• Limiting your consumption of salty foods (even those salty chips you may be craving)
• Doing light aerobic exercises (like walking) 
• Studies have also shown taking a daily magnesium supplement can help ease PMS bloating and some other PMS symptoms, including breast tenderness⁶.

PMS anxiety

If you feel like your mood changes right before your period, you’re not alone. Mood changes can be a very real symptom of PMS with many women experiencing mild anxiety symptoms. 

Those with PMS may experience⁸:

• Increased menstrual cycle mood swings
• Increased irritability or sensitivity 
• Feelings of low mood 
• Anxiety symptoms 

While some mood changes are totally normal, it’s important to get advice from a doctor if you feel your menstrual cycle and mood are impacting your day-to-day life.

PMS fatigue

A dip in energy levels in your menstrual cycle is a totally normal thing for many people. In fact, it’s even suggested to be one of the most common PMS symptoms⁹. 

But, why exactly does it happen? Studies suggest that PMS might actually interfere with your sleep by interrupting stage 2 and REM sleep¹⁰. These nightly disturbances can leave you feeling tired, and even impact your mood too⁹. 

People who experience heavy periods, known as menorrhagia, may also tend to feel tired during their periods, which may be linked to other potential health concerns, like low iron . If you’re struggling with fatigue, it’s always best to speak to your doctor¹¹.

Keen to learn more? Check out the Swisse Wellness Hub for more women’s health. Explore the different stages of the menstrual cycle, as well as the hormones at play during each stage.  

References:

1. Period Pain [Internet]. Medlineplus.gov. National Library of Medicine; 2019. Available from: https://medlineplus.gov/periodpain.html
   
2. NHS. PMS (premenstrual syndrome) [Internet]. NHS. 2019. Available from: https://www.nhs.uk/conditions/pre-menstrual-syndrome
   
3. Australia H. Premenstrual syndrome (PMS) [Internet]. www.healthdirect.gov.au. 2020. Available from: https://www.healthdirect.gov.au/premenstrual-syndrome-pms
   
4. OASH. PMS relief [Internet]. womenshealth.gov. 2018. Available from: https://www.womenshealth.gov/menstrual-cycle/premenstrual-syndrome
   
5. Kick PMS bloat to the curb [Internet]. Mayo Clinic. Available from: https://www.mayoclinic.org/healthy-lifestyle/womens-health/in-depth/water-retention/art-20044983
   
6. WALKER AF, DE SOUZA MC, VICKERS MF, ABEYASEKERA S, COLLINS ML, TRINCA LA. Magnesium Supplementation Alleviates Premenstrual Symptoms of Fluid Retention. Journal of Women’s Health. 1998 Nov;7(9):1157–65.
   
7. Corinne O'Keefe Osborn. How to Deal with Anxiety Before Your Period [Internet]. Healthline. Healthline Media; 2019 [cited 2024 Oct 1]. Available from: https://www.healthline.com/health/anxiety-before-period#pmdd-and-pme
   
8. Menstrually Related Mood Disorders [Internet]. Center for Women’s Mood Disorders. Available from: https://www.med.unc.edu/psych/wmd/resources/mood-disorders/menstrually-related/
   
9. Fatigue Before a Period: Causes and 7 Ways to Boost Your Energy [Internet]. Healthline. 2019. Available from: https://www.healthline.com/health/womens-health/fatigue-before-period#2
   
10. Jehan S, Auguste E, Hussain M, Pandi-Perumal SR, Brzezinski A, Gupta R, et al. Sleep and Premenstrual Syndrome. Journal of sleep medicine and disorders [Internet]. 2016;3(5). Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5323065/
11. Sutton E. Why You Should Not Ignore Tiredness during Your Period | Menorrhagia [Internet]. London Women’s Centre. 2019. Available from: https://www.londonwomenscentre.co.uk/info/news/not-ignore-tiredness-period