You've heard it your whole life.

From your mum. From a doctor who spent three minutes with you. From every woman around you who just got on with it.

"It's normal. All women go through it. Take a painkiller and carry on."

Here's the thing: common isn’t the same as normal.

Pain that stops you from going to work, showing up at the gym, or getting out of bed deserves attention. And you've been let down every time someone told you to just push through it.

So what's actually causing it?

In most cases, period pain (called primary dysmenorrhea) is driven by a very specific biological mechanism.

The role of prostaglandins

Each month, your uterus sheds its lining.
 To help this process, your body releases compounds called prostaglandins.

These compounds:

●      trigger uterine contractions

●      help expel the lining

This is completely normal.

When prostaglandins are higher than usual

In some individuals, prostaglandin levels are elevated.

This has measurable effects:

●      Stronger uterine contractions

●      Reduced blood flow to uterine tissue (ischemia)

●      More intense pain

Prostaglandins can also enter the bloodstream, which explains why some people experience:

●      nausea

●      diarrhoea

●      headaches

●      dizziness

These symptoms are well-documented in clinical research on dysmenorrhea.

This is not about pain tolerance

Multiple studies have shown that individuals with more severe menstrual pain tend to have higher levels of prostaglandins in menstrual fluid.

This means the difference is not just psychological — it is biochemical.

Why your pain can vary from month to month

If prostaglandins are the driver, why does pain fluctuate across cycles?

The role of physiology and context

Prostaglandin production is influenced by hormonal signalling, but the experience of pain is also shaped by broader physiological factors.

Research shows that:

●      Stress can increase pain sensitivity

●      Poor sleep can amplify inflammatory signalling and pain perception

●      Fatigue and lifestyle factors can reduce your body’s ability to regulate discomfort

So while we cannot say that stress or diet directly “increase prostaglandins” in a simple, linear way, we can say that they meaningfully influence how intense the pain feels.

This explains a common experience: some cycles feel manageable; others feel overwhelming.

Where painkillers fit in

Non-steroidal anti-inflammatory drugs (NSAIDs) — like ibuprofen or mefenamic acid — are commonly used for period pain.

They work by inhibiting COX (Cyclooxygenase) enzymes, thereby reducing prostaglandin production.

This is why they are effective.

But there’s an important limitation

NSAIDs act during the episode.

They reduce prostaglandins temporarily, to relieve pain in the moment.

But they do not necessarily change why prostaglandin levels are higher in some individuals, or why pain recurs cycle after cycle.

This is why many people find themselves repeating the same cycle every month.

When period pain may signal something more

Not all period pain is primary dysmenorrhea. In some cases, severe pain can indicate an underlying condition.

Endometriosis

One of the most common is endometriosis.

This is a condition where tissue similar to the uterine lining grows outside the uterus. It is estimated to affect ~10% of women globally.Common symptoms include:

●      severe menstrual pain

●      pain during sex

●      chronic pelvic pain

●      fatigue

The diagnosis gap

On average, it takes 7–10 years to diagnose endometriosis. One of the biggest reasons: Severe pain is often dismissed as “normal.”

And there can be a number of other conditions that severe period pain indicates, including:

Adenomyosis: Endometrial-like tissue grows into the muscular wall of the uterus.

Uterine Fibroids: Benign (non-cancerous) growths in the uterus.

Pelvic Inflammatory Disease: Infection of the reproductive organs (often from untreated STIs).

Ovarian cysts: Fluid-filled sacs on the ovaries.

When to seek help

If your pain:

●      significantly disrupts daily life

●      is worsening over time

●      is associated with other symptoms

…it’s worth consulting a gynaecologist, not just managing symptoms on your own.

A more useful way to think about period pain

Instead of asking “is this normal?”, a better question is “What is driving this pain in my body?”

Because in most cases, there is a driver:

●      prostaglandin activity

●      uterine contractions

●      systemic sensitivity to pain

●      or an underlying condition

What this means for you

A few grounded takeaways:

1. Period pain has a biological basis

It is not something you’re imagining or exaggerating.

2. Severity varies for real physiological reasons

Hormones, stress, sleep, and overall health all play a role in how pain is experienced.

3. Relief and root cause are not always the same

Treatments that reduce pain in the moment don’t always address why it keeps recurring.

4. Severe pain deserves investigation

Especially if it interferes with your ability to function.

The bottom line

Period pain is one of the most commonly normalised forms of pain.

But common does not mean something you have to silently tolerate.

There is biology behind it. There is variation in it. And in some cases, there are underlying conditions worth identifying.

Understanding what’s driving your pain is the first step toward managing it more effectively — and, where possible, reducing it over time.