Functional Medicine · Hormonal Health

The Journal

by Dr. Natasha Ryan, ND

Cycles · Pelvic Pain

Painful Periods or Endometriosis? What's Normal Cramping and What Isn't

5 min read

You plan your month around two days. You know which meetings to move, which painkillers to stock, and how many layers to wear so no one notices. Since you were a teenager, everyone has told you the same thing: periods hurt, and some women just have bad ones.

Period pain is common. Pain that takes over your life isn't normal, and it deserves a proper look.

Normal cramps vs. something more

Cramping comes from prostaglandins, chemicals released by the uterine lining that make the uterus contract. Higher prostaglandins mean stronger cramps. This is called primary dysmenorrhea: real pain, but no disease behind it.

Secondary dysmenorrhea is period pain caused by a condition, most often endometriosis or adenomyosis.

Usually primary (common cramps) Points toward something more
Starts in your teens, soon after your periods began Gets worse over the years, or starts later in life
Lasts one to three days, at the start of bleeding Starts days before bleeding, or lasts the whole period
Responds well to ibuprofen or naproxen Ibuprofen barely touches it
Pain is only during your period Pelvic pain at other times of the month too
No other symptoms Pain with sex, bowel movements, or urination; heavy bleeding; bloating

Endometriosis

Endometriosis is when tissue similar to the uterine lining grows outside the uterus, on the ovaries, the pelvic lining, the bowel, or the bladder. It responds to hormones, causing inflammation, pain, and scar tissue.

The World Health Organization estimates it affects about 10% of reproductive-age women, or 190 million worldwide. It's one of the most common causes of chronic pelvic pain.

The symptoms

  • Severe period pain that gets worse over time
  • Pelvic pain between periods
  • Pain during or after sex, especially deep pain
  • Painful bowel movements or urination, especially during your period
  • Bloating, often called "endo belly," nausea, and fatigue
  • Heavy periods
  • Difficulty getting pregnant

Endometriosis is often mistaken for IBS, because bowel symptoms are so common. If your "IBS" flares with your cycle, it's worth asking about endometriosis.

Why it takes so long to diagnose

According to the WHO, the average time from first symptoms to diagnosis is between 4 and 12 years. A 2024 University of York review of 22 studies put the global average at about 6.6 years. A big part of the delay is that period pain gets dismissed, by doctors and by women themselves.

Adenomyosis: the one most women haven't heard of

Adenomyosis is a cousin of endometriosis. The uterine lining grows into the muscle wall of the uterus itself. The uterus becomes enlarged and tender.

It typically causes heavy periods and painful periods together, and it's often found in women in their late 30s and 40s, sometimes alongside endometriosis or fibroids. It can now be seen on a good pelvic ultrasound or MRI. If you're in your 40s with periods that are getting both heavier and more painful, ask specifically about adenomyosis. For more on heavy bleeding at this stage, see Heavy and Irregular Periods in Perimenopause.

You don't need surgery to start treatment

For years, the only way to diagnose endometriosis was laparoscopy, a surgery to look inside the pelvis. That's a big reason women waited so long.

The 2022 European Society of Human Reproduction and Embryology (ESHRE) guideline changed this. Laparoscopy is no longer the gold standard for diagnosis. Instead:

  • Diagnosis can be based on symptoms, an exam, and imaging such as ultrasound or MRI
  • Hormonal treatment can be started based on symptoms, without surgical confirmation
  • Laparoscopy is recommended mainly when imaging is negative and treatment hasn't worked

A normal ultrasound doesn't rule out endometriosis, because small lesions don't always show. But it does mean you don't have to wait for surgery to get relief.

What helps

Anti-inflammatories, taken the right way

NSAIDs like ibuprofen and naproxen block prostaglandins. A Cochrane review of 80 trials found about 45% to 53% of women got moderate or excellent relief from NSAIDs, compared with about 18% on placebo. They worked better than acetaminophen.

The trick is timing. Start them a day before your period is due, or at the very first sign of it, and take them on a regular schedule for the first day or two, rather than waiting until the pain is severe.

Hormonal treatment

Because endometriosis and adenomyosis are driven by estrogen, treatment usually works by quieting the cycle:

  • Hormonal birth control, often taken continuously to skip periods
  • Progestins, including the hormonal IUD and progestin-only pills
  • GnRH antagonists, such as relugolix combination therapy (Myfembree), approved by the FDA in 2022 for endometriosis pain. In the trials, 75% of women had a significant drop in period pain, compared with about 27% to 30% on placebo.

Surgery to remove endometriosis is still an option, especially when other treatment hasn't worked.

Supporting the bigger picture

Endometriosis is an inflammatory condition, and estrogen balance matters. These don't replace medical treatment, but they support it:

  • Pelvic floor physical therapy. Chronic pelvic pain often leaves the pelvic floor muscles tight and guarded. Physiotherapy is listed by the WHO as one of the approaches that can reduce pain.
  • Heat. A heating pad on the lower abdomen is simple, and many women find it helps.
  • Gut health and estrogen clearance. Your gut bacteria help decide how much estrogen gets recycled back into circulation. See The Estrobolome.
  • An anti-inflammatory way of eating, with plenty of vegetables, fiber, and omega-3-rich fish.
  • Support for the pain itself. Chronic pain changes how the nervous system processes signals. The WHO notes that cognitive behavioral therapy can reduce pain and improve quality of life.

When to see someone

Get evaluated if:

  • Period pain keeps you from work, school, or plans
  • Ibuprofen or naproxen, taken properly, don't control it
  • You have pelvic pain outside your period, pain with sex, or painful bowel movements
  • Your periods are getting heavier and more painful over time

And get urgent care for sudden, severe one-sided pelvic pain, pain with fever, or pain with a positive pregnancy test.

What you can do now

  1. Track your pain for two or three cycles: when it starts, how bad, what helps, and any bowel, bladder, or sex-related pain.
  2. Try NSAIDs the right way: early and on a schedule.
  3. Ask for a pelvic ultrasound, and mention endometriosis and adenomyosis by name.
  4. Know that you don't need surgery to start treatment.

Painful periods are common. That doesn't make them something you have to live with.

References

  1. World Health Organization. Endometriosis fact sheet. 2025. View source
  2. University of York. Diagnosing endometriosis: review of diagnostic delay. 2024. View source
  3. Becker CM, et al. ESHRE guideline: endometriosis. Hum Reprod Open. 2022. View source
  4. Updated endometriosis guidelines emphasize less laparoscopy, more hormone therapy. MDedge. 2022. View source
  5. Marjoribanks J, Ayeleke RO, Farquhar C, Proctor M. Nonsteroidal anti-inflammatory drugs for dysmenorrhoea. Cochrane Database Syst Rev. 2015. View source
  6. FDA approves Myfembree for endometriosis pain. Contemporary OB/GYN. August 2022. View source