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Health condition

Painful periods, and knowing when it's more than dysmenorrhoea.

Painful periods are common and usually respond well to properly timed treatment. This guide covers the essentials - for a fuller look at causes and management, see our menstrual cramps guide.

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Why trust this guide

  • 01

    Editorial team

    Written by our editorial team from the UK sources listed on each page.

  • 02

    Sourced from guidance

    Checked against NICE CKS and RCOG sources you can see at the end.

  • 03

    Current for 2026

    Reflects NICE CKS dysmenorrhoea guidance on NSAID timing, hormonal options and when to refer.

Key facts

Painful periods at a glance.

The essentials, in plain English - what dysmenorrhoea is, the two types, and how it's treated in the UK today.

  • What it is

    Dysmenorrhoea - crampy lower abdominal pain around menstruation, one of the most common gynaecological complaints.

  • Primary dysmenorrhoea

    No underlying pathology - caused by excess prostaglandin release from the uterine lining as it sheds.

  • Secondary dysmenorrhoea

    Pain caused by an underlying condition such as endometriosis, adenomyosis, fibroids or PID.

  • First-line treatment

    NSAIDs - mefenamic acid, ibuprofen or naproxen - started early, before pain builds.

  • Hormonal options

    The combined pill or the levonorgestrel intrauterine system reduce pain and flow together.

  • When to worry

    Progressive pain, pain outlasting bleeding or deep dyspareunia point towards a secondary cause.

Want the fuller picture?

Our menstrual cramps guide covers this topic in depth.

"Painful periods" and "menstrual cramps" describe the same clinical picture, dysmenorrhoea. If you want the fully detailed version - with a longer symptom breakdown, a wider treatment ladder and a more detailed diagnostic pathway - read our menstrual cramps guide.

Read the full guide

How the diagnosis is made

From painful periods to a clear plan.

The steps a UK GP or gynaecologist will normally follow, in order.

  1. 01

    Assessing

    Pain and cycle history

    When pain started relative to menarche, its pattern, and how it has changed over time.

  2. 02

    Assessing

    Screen for red flags

    Deep dyspareunia, abnormal bleeding, subfertility or pain outside the period suggest a secondary cause.

  3. 03

    Confirming

    Examination and imaging

    A pelvic exam and transvaginal ultrasound if secondary dysmenorrhoea is suspected.

  4. 04

    Preparing

    Trial of first-line treatment

    NSAIDs with or without hormonal contraception, reviewed after two to three cycles.

  5. 05

    Preparing

    Gynaecology referral

    For suspected endometriosis, adenomyosis or fibroids, or when standard treatment fails.

Typical timeline: a first visit to a settled plan within two to three cycles.

Symptoms

What painful periods actually feel like.

The classic pattern of primary dysmenorrhoea - and the features that mean it's worth looking more closely.

  • Crampy lower abdominal pain

    Pain that may radiate to the back or thighs - the hallmark symptom of dysmenorrhoea.

  • Starts with or just before bleeding

    Primary dysmenorrhoea typically lasts one to three days from the onset of the period.

  • Nausea or loose stools

    Prostaglandin-driven gut effects are common alongside cramping.

  • Pain that is changing or worsening

    A pattern that progresses cycle after cycle suggests a secondary cause.

  • Deep dyspareunia

    Pain during deep penetration points towards endometriosis or adenomyosis.

  • Red flag - pain outlasting the period

    Cramping that continues after bleeding stops deserves gynaecology assessment.

Treatment

How painful periods are treated in the UK.

NSAIDs first, hormonal options next, and a proper look for secondary causes when standard treatment does not work.

  • NSAIDs

    Mefenamic acid, ibuprofen or naproxen - first-line, best started before or at the onset of bleeding.

  • Combined oral contraceptive pill

    Reduces both pain and flow, and provides contraception if wanted.

  • Levonorgestrel intrauterine system

    Mirena - effective long-acting option for pain and contraception together.

  • Heat therapy

    A hot water bottle or heat pad - simple, safe and genuinely evidence-based.

  • Lifestyle measures

    Regular exercise and stopping smoking, which is linked to worse dysmenorrhoea.

  • Investigating secondary causes

    Transvaginal ultrasound and referral when endometriosis, adenomyosis or fibroids are suspected.

What this guide is based on

The sources behind every claim on this page.

UK national guidance and specialist society standards, current at the time of last review.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your GP or gynaecologist knows your history and can tell you which parts apply to you. If in doubt, get seen.

  • NICE Clinical Knowledge Summaries (CKS). Dysmenorrhoea.

  • Royal College of Obstetricians and Gynaecologists (RCOG). Guidance on dysmenorrhoea and endometriosis.

  • NICE. Endometriosis: diagnosis and management (NG73).

Red flags

When period pain needs closer attention.

Most period pain is manageable in primary care. These are the situations that aren't.

  • Pain outlasting the period

    Cramping that persists beyond bleeding is unusual for primary dysmenorrhoea.

  • Progressive worsening

    Pain that gets worse cycle after cycle suggests endometriosis or adenomyosis.

  • Deep dyspareunia or subfertility

    Classic features suggesting a secondary cause needing gynaecology review.

  • Fever with pelvic pain

    Raises the possibility of pelvic inflammatory disease - needs prompt assessment.

  • Sudden severe unilateral pain

    Can indicate ovarian torsion or a ruptured cyst - this needs emergency care.

  • No response to standard treatment

    Failure of NSAIDs and hormonal options after a fair trial signals further investigation.

Living with it

A manageable condition, with a clear ladder.

Four things that make the biggest difference month to month.

A quiet reminder

Painful periods are common - they don't have to be unbearable.

There is a well-tested ladder of treatment. If you are still on the bottom rung after months of trying, it is time to ask for the next step.

  1. 01 Timing

    Start NSAIDs early

    Taking mefenamic acid or ibuprofen just before or at the first sign of bleeding works better than waiting.

  2. 02 Heat

    Use a hot water bottle

    Heat therapy is simple, safe and supported by evidence for easing cramps.

  3. 03 Track

    Keep a pain diary

    Recording pain over a few cycles makes it easier to spot a secondary pattern.

  4. 04 Escalate

    Don’t normalise severe pain

    Pain that disrupts school or work deserves a proper review, not just paracetamol.

Frequently asked

Everything we get asked about painful periods.

Quick answers on causes, painkillers, hormonal options and endometriosis.

  • What causes painful periods?

    Most painful periods are primary dysmenorrhoea - excess prostaglandin release causes the uterine muscle to contract and blood vessels to narrow, with no underlying pelvic disease. See our full menstrual cramps guide for a detailed look at the mechanism and management.

  • What is the difference between primary and secondary dysmenorrhoea?

    Primary dysmenorrhoea has no underlying pathology and typically starts soon after periods begin. Secondary dysmenorrhoea is caused by a condition such as endometriosis, adenomyosis, fibroids or pelvic inflammatory disease, and often develops later or changes pattern over time.

  • What is the best treatment for period pain?

    NSAIDs such as mefenamic acid, ibuprofen or naproxen are first-line and most effective when started just before or at the onset of bleeding. Hormonal options such as the combined pill or the levonorgestrel intrauterine system are useful next steps.

  • When should painful periods be investigated?

    When pain worsens over time, persists after the period ends, is associated with deep dyspareunia or subfertility, or does not respond to NSAIDs and hormonal treatment after a fair trial. These features point towards a secondary cause.

  • Could painful periods be endometriosis?

    It is a key differential, especially with progressively worsening pain, deep dyspareunia or subfertility. A gynaecology referral for transvaginal ultrasound, and sometimes laparoscopy, is appropriate if standard treatment does not help.

  • Is heat therapy actually effective for period pain?

    Yes. A hot water bottle or heat pad applied to the lower abdomen is a simple, evidence-supported measure that can be used alongside NSAIDs for additional relief.

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