Do you suffer from back pain, bloating, cramping, headache, a change in your bowel habits, or swollen, tender breasts leading up to your menstrual bleed?

Maybe you face predominantly psychological symptoms — feeling anxious, down, irritable, or tired, craving unhealthy foods, or finding that your sex drive has disappeared.

Maybe your behaviour changes, and you uncontrollably cry as you tuck into bowls of ice cream or scoff down chocolate.

Premenstrual syndrome (PMS) can be challenging!

Yet, it’s super common. Nine in ten experience some signs or symptoms. Sometimes symptoms are mild, occasionally moderate, and for an unfortunate group, the severity profoundly impacts daily life. Of course, this can vary depending on the month.

So, what is PMS?

What is premenstrual syndrome?

If you experience PMS, you already have a pretty good idea. You’ve likely talked to friends and family and recognized their experiences too. But so we can compare apples with apples, let’s look at the medical definition.

PMS is defined as “a recurring pattern of symptoms that occur during the premenstrual phase and decline soon after the start of menses.” Symptoms occur in the luteal phase after ovulation and before a period.

To be diagnosed with PMS, symptoms must occur only in this menstrual cycle phase. If they’re present in the first half, the follicular phase, then it’s something else.

Speaking of “something else,” other causes for the symptomatic picture should be ruled out before a diagnosis of PMS is reached. There might be an underlying condition responsible; knowing this, you can find tailored treatment.

But if you do have PMS, know that the symptoms can be broad, including behavioural, emotional and psychological, and physical. We’ll dive into this momentarily.

Just one last point before we do: symptoms must occur for at least two cycles to fit the medical definition.

What symptoms are common in PMS?

Many! This common syndrome can manifest in a variety of ways. Let’s break them down into the categories we listed above.

Behavioral symptoms:

  • Decreased interest or motivation in usual activities
  • Difficulty managing daily tasks or responsibilities
  • Emotional outbursts
  • Food cravings, especially for carbohydrates or sweets (chocolate ice cream, anyone?)
  • Increased appetite or changes in eating patterns
  • Social withdrawal or increased desire for alone time

Emotional and psychological symptoms:

  • Anxiety and feelings of tension
  • Changes in sex drive (libido)
  • Crying bursts
  • Depression or feelings of sadness
  • Difficulty concentrating or focusing
  • Emotional sensitivity
  • Feelings of overwhelm or being out of control
  • Forgetfulness
  • Increased emotional sensitivity
  • Insomnia or changes in sleep patterns
  • Loss of confidence
  • Mood swings and irritability
  • Nervousness

 Physical symptoms:

  • Abdominal bloating and water retention
  • Breast tenderness and swelling
  • Digestive issues (like constipation, diarrhea, or nausea)
  • Dizziness
  • Fatigue and low energy levels
  • Headaches and migraines
  • Muscle aches and joint pain
  • Skin changes (acne, breakouts, or sensitivity)
  • Swelling of the feet or hands
  • Weight gain

It’s a lot! While women don’t face all these symptoms, most experience at least one.

Note: For some women, symptoms are profound and disabling. Premenstrual dysphoric disorder (PMDD) affects up to 5% of women and follows a similar cyclical pattern.

What causes PMS?

You’d imagine, given that this syndrome affects the majority of half the population, we’d have definite answers by now. Sadly, we don’t. What we have are theories.

The article Premenstrual Syndrome, a Common but underrated entity: a review of the clinical literature, discussed two important candidates.

Firstly, PMS is sparked by sex hormone fluctuations in the luteal phase of the menstrual cycle “in susceptible women.” (If the statistic of 90% of women experiencing PMS is accurate, that makes most of us “susceptible”!)

Secondly, the nervous system is involved. This includes neurotransmitters — chemical messengers released by nerve cells that affect other cells like serotonin — and the autonomic nervous system — the “fight or flight” system that deals with stress.

PMS: the sex hormone connection

This is an obvious connection, right?

The fluctuation of sex hormones like estrogen and progesterone after ovulation is significant: when PMS kicks in.

As we said in our article, The Impact of Hormone Imbalance on Mood and Emotional Well-Being, “PMS is thought to involve a “hormonal disproportion like estrogen surplus and progesterone deficiency.” Too much estrogen and too little progesterone may put them in an imbalance.

Research shows that estrogen and progesterone are involved in a common symptom of PMS: mood. In one study, the authors said that progesterone has “likely causal factors for the mood symptoms experienced by women with premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD).”

But sex hormones do more than affect mood. Their cyclical changes impact central neurotransmitters.

PMS: the nervous system and neurotransmitter connection

While we can fall into the trap of thinking one body system is separate from another, this isn’t how biology works. We, humans, are beautiful, complex interrelationships of cells and chemical messengers like hormones and neurotransmitters.

So it’s unsurprising that the hormonal and nervous systems influence one another. That’s how we’re designed!

Regarding PMS, there are various interactions at work. 

As estrogen decreases in the latter part of the luteal phase, the brain releases the neurotransmitter and hormone norepinephrine. This stimulates a drop in neurotransmitters, including acetylcholine, dopamine, and serotonin. Enter depression, fatigue, and insomnia!

And you might have noticed the nervous system in action yourself. Stress triggers the activity of the “fight or flight” system. This increases the intensity of uterine contraction and escalates menstrual pain. That’s one reason you may experience worsening premenstrual syndrome symptoms when you are under the pump. 

It’s also why lifestyle approaches and supplemental support matter greatly. But that’s a topic for the next article in our 6-part series!

The takeaway 

Premenstrual syndrome is widespread. Its wide-ranging symptoms span physical signs, emotional and psychological turbulence, and behavioural challenges. This syndrome can alter our ability to be in and cope with our lives.

While science doesn’t yet understand the intricacies of PMS, we know that hormones like estrogen and progesterone play an important role. As does the nervous system and its neurotransmitters.

Wonderfully, there is evidence that points to practical natural treatment approaches. But that’s a topic for the next article in our women’s hormone health series. (Check it out here!)