Cycle × body · 6 min
Painful periods — what causes them and when to start diagnostics
Painful periods (dysmenorrhea) are not a character defect and not "a woman's lot". It's a medical concept with a clear split: primary (no underlying disease, physiological) and secondary (a symptom of a specific condition, e.g., endometriosis). The distinction matters because it changes what to do.
Primary dysmenorrhea
The most common form, affecting 50–90% of menstruating people. It comes from overproduction of prostaglandins — substances that drive uterine contractions during endometrial shedding. Characteristics:
- Pain starts on the day menstruation begins or a few hours earlier.
- Lasts 1–3 days, peaks in the first 24 hours.
- Located in the lower abdomen, sometimes radiating to lower back and thighs.
- May come with nausea, diarrhea, headache, fainting.
- Responds well to NSAIDs (ibuprofen, naproxen) taken prophylactically.
Secondary dysmenorrhea
Pain with a specific underlying cause. Most commonly:
- Endometriosis — pain starts 5–10 days before menstruation, builds through it, sometimes painful intercourse or bowel movements.
- Adenomyosis — very heavy, painful periods, most often after 35.
- Uterine fibroids — pressure, very heavy bleeding.
- Pelvic inflammatory disease (PID) — constant pain, not only during menstruation.
- Anatomical anomalies of the uterus.
Red flags — when to see a doctor
- Pain starts days before menstruation, not with it.
- NSAIDs stop working, or you keep needing higher doses.
- Pain causes vomiting, fainting, or ≥1 missed workday per month.
- Pain during intercourse, urination, or bowel movements during menstruation.
- Pain has worsened over the last months/years.
- Bleeding between periods has been added in.
Why diagnosis is delayed
Average diagnostic delay for endometriosis in Europe is 7–10 years. Why: menstrual pain is so widely normalized that the patient rarely says "this is too much" and the clinician rarely asks. With a log from 2–3 cycles (when it starts, how intense, how long, what helps, life impact), the conversation becomes specific and diagnostics moves.
What actually helps in primary dysmenorrhea
- NSAIDs taken 1–2 days before expected pain (strongest evidence).
- Heat on the lower abdomen — comparable to mild NSAIDs.
- Continuous hormonal contraception — eliminates bleeding and pain for most.
- Magnesium 300–400 mg/day in the second half of the cycle — moderate evidence.
- Vitamin B1 (100 mg/day) — several studies show efficacy.
- Regular low-to-moderate physical activity.
- TENS (transcutaneous electrical nerve stimulation) — evidence in primary menstrual pain.
What does NOT help (myth)
- "Pregnancy will cure painful periods" — it's a myth. Pain often returns postpartum, and pregnancy is not a treatment for endometriosis.
- Elimination diets without indication — placebo, or unrelated to the pain mechanism.
- "Uterus-detox" supplements — anatomically impossible, marketing-effective.
What's worth logging
Day pain starts, intensity (1–10), duration, what helped, whether you had to stay in bed. Two months of this data is the difference between "I think my periods are bad" and "for 6 months pain has started 4 days before menstruation and lasted through day 3, NSAIDs help partially". The second sentence opens diagnostics.