Period pain is so common among teenage girls that it is often dismissed – by parents, by friends, and sometimes by healthcare professionals – as something to be tolerated rather than treated. This dismissal can mean years of unnecessary suffering, and it can also mean missing a significant underlying condition.
The distinction between ordinary period pain and something that needs attention comes down to a few practical questions: how severe is the pain, how reliably does it respond to treatment, and is it getting better or worse? Pain that puts a teenager to bed for a day or two each month, that doesn't shift with ibuprofen, or that is worsening cycle by cycle is not typical and deserves proper assessment.
Healthbooq (healthbooq.com/apps/healthbooq-kids) covers menstrual health in teenagers and adolescent wellbeing.
The Basics of Primary Dysmenorrhea
Primary dysmenorrhea is period pain with no identifiable underlying cause. It is driven by prostaglandins – hormone-like chemicals produced by the endometrium (uterine lining) during menstruation. High prostaglandin levels trigger uterine muscle contractions that reduce blood flow to the uterus, causing the cramping pain. They also cause the nausea, loose stools, and light-headedness that accompany severe period pain in many teenagers.
The pain typically starts in the first day or two of a period, is cramping in character, felt in the lower abdomen and often radiating to the lower back or thighs, and tends to ease over the course of the period. It often begins within a year or two of the first period, when ovulatory cycles become established – prostaglandin production is higher in ovulatory than anovulatory cycles.
Prevalence studies consistently find that 45-90% of adolescent girls experience some degree of period pain, with estimates varying by how severe or disabling the pain needs to be to count. Research by Bettina Pfleiderer and colleagues in Germany found that around 15-20% of teenagers miss school due to period pain each month – a figure that reflects both the frequency and severity of the problem in this age group.
Treating Primary Dysmenorrhea
Non-steroidal anti-inflammatory drugs (NSAIDs) – ibuprofen and mefenamic acid – are first-line treatment and are substantially more effective than paracetamol. They work by inhibiting prostaglandin synthesis: less prostaglandin, less uterine contraction, less pain. The key to using NSAIDs effectively for period pain is starting them the day before the period begins (or as soon as it starts) rather than waiting until pain is already severe. This pre-emptive use takes advantage of the prostaglandin synthesis window and is significantly more effective than reactive dosing.
Ibuprofen 400mg three times daily is a standard dose for adults. For teenagers, the appropriate dose is weight and age dependent; NICE guidance confirms ibuprofen as the preferred analgesic for period pain in this age group. Mefenamic acid (Ponstan) 500mg three times daily is an alternative that some find more effective; it requires a prescription.
Heat – a hot water bottle or heat pad over the lower abdomen – has genuine evidence of efficacy. A Cochrane review by Wilson and colleagues confirmed that continuous low-level local heat is comparable to NSAIDs for mild-to-moderate dysmenorrhea. It is particularly useful for teenagers who want to avoid medication.
If NSAIDs alone are insufficient, the combined oral contraceptive pill significantly reduces period pain in most cases. By suppressing ovulation, it reduces prostaglandin production; by creating a thinner endometrium, it reduces the amount of tissue shedding. It is an effective treatment for period pain in teenagers who are appropriate candidates, independent of any contraceptive intention.
When to Suspect Something More
Primary dysmenorrhea tends to respond predictably to NSAIDs and, if needed, to hormonal treatment. When it doesn't respond, when the pain is severe enough to cause regular school absence, or when it is worsening over time, secondary dysmenorrhea – pain with an underlying cause – becomes the concern.
Endometriosis is by far the most important cause of secondary dysmenorrhea in teenage girls. It is a condition in which tissue similar to the endometrium grows outside the uterus – on the ovaries, fallopian tubes, bowel, or pelvic peritoneum – causing inflammation, scarring, and pain. The mechanism of pain in endometriosis involves local prostaglandin release, nerve sensitisation, and inflammation, which is why it often responds partially to NSAIDs but not completely.
The diagnostic delay for endometriosis in the UK is, on average, 7-8 years from symptom onset, according to research by the charity Endometriosis UK and studies published by Andrew Horne at the University of Edinburgh. The delay is partly because symptoms are dismissed as normal period pain, partly because diagnosis requires laparoscopy (surgery) to confirm, and partly because awareness of the condition's prevalence in adolescents has historically been low. Around 10% of women of reproductive age have endometriosis, and symptoms frequently begin in adolescence.
Features that raise the possibility of endometriosis include: pain that starts before the period (not just with it), pain that persists throughout the period rather than improving, pain with bowel movements or urination during a period, pain during intercourse (in sexually active teenagers), and cyclical symptoms in the weeks before the period. Regular school absence from period pain is independently associated with endometriosis at laparoscopy.
Other causes of secondary dysmenorrhea include adenomyosis (endometrial tissue within the uterine muscle wall, more common in older women but increasingly recognised in adolescents), pelvic inflammatory disease (in sexually active girls), ovarian cysts, and, rarely, structural abnormalities of the reproductive tract.
Getting Help
A teenager with period pain severe enough to limit activities deserves a proper clinical assessment – not reassurance that this is normal. At the GP, the conversation should include how severe the pain is, which cycle day it starts and ends, whether it responds to ibuprofen (taken appropriately), whether there are associated bowel or bladder symptoms, and whether it is getting worse over time.
Keeping a symptom diary for two or three cycles before the GP appointment – noting when pain starts, severity on a simple 1-10 scale, what it prevents her from doing, and what has helped – is practical and gives the GP the detail needed to make a useful assessment.
If NSAIDs and the combined pill haven't provided adequate control, or if features suggesting endometriosis are present, a gynaecology referral is appropriate. NICE guidelines on endometriosis (NG73, 2017) recommend that primary care clinicians do not exclude a diagnosis of endometriosis based on a normal pelvic ultrasound: ultrasound cannot see peritoneal endometriosis, which is the most common type in adolescents.
The Endometriosis UK charity provides a helpline, patient resources, and specialist centre information for young women in this position.
Key Takeaways
Period pain (dysmenorrhea) affects up to 90% of adolescent girls to some degree, and around 15-20% have pain severe enough to limit daily activities. Most cases are primary dysmenorrhea – pain caused by prostaglandin-driven uterine contractions – which is well managed with ibuprofen and, if needed, hormonal treatment. Secondary dysmenorrhea has an underlying cause; endometriosis is the most important, and it is substantially underdiagnosed in teenagers, with an average diagnostic delay of 7-8 years from symptom onset in the UK. Pain that is severe, worsening, not responding to ibuprofen, or causing significant school absence warrants investigation.
