Dysmenorrhoea

NICE CKS Dysmenorrhoea. Last Revised Oct 2023.

Article Last Updated:21/04/2026

Dysmenorrhoea

Dysmenorrhoea refers to painful menstrual cramps occurring shortly before and/or during menstruation. It is a symptom rather than a diagnosis, and may be primary (no underlying pelvic pathology) or secondary to conditions such as endometriosis, adenomyosis, or fibroids.

This updated UKMLA guide to dysmenorrhoea, based on NICE CKS covers classification, causes, diagnosis, and management.

Definition

Dysmenorrhoea, also known as menstrual pain, refers to painful lower abdominal cramping that occurs shortly before and/or during menstruation.

Dysmenorrhoea is a symptom, not a disease or pathology in itself. It may be caused by an underlying condition.

Types of Dysmenorrhoea

Type	Description
Primary dysmenorrhoea	Dysmenorrhoea with no identifiable underlying pelvic pathology
Secondary dysmenorrhoea	Dysmenorrhoea caused by an underlying pelvic pathology

Causes and Risk Factors

Primary Dysmenorrhoea

Primary dysmenorrhoea is thought to be caused by the production of uterine prostaglandins during menstruation

Prostaglandins stimulate uterine myometrial contractions → decreased blood flow → uterine hypoxia → pain
Further effects of prostaglandins on smooth muscles may manifest as GI symptoms (e.g. vomiting, nausea and diarrhoea), which frequently co-exist with primary dysmenorrhoea

Risk factors for primary dysmenorrhoea include:

Early menarche
Heavy menstrual bleeding
Nulliparity
Family history of dysmenorrhoea
Emotional stress

Primary dysmenorrhoea has also been associated with:

BMI <20 kg/m²
Smoking
History of sexual abuse

Secondary Dysmenorrhoea

Endometriosis – leading cause
Adenomyosis
Fibroids
Pelvic inflammatory disease
Intrauterine device insertion
Ovarian / cervical cancer

Assessment, Investigation and Diagnosis

Conduct:

Detailed history
Abdominal examination
Pelvic examination, including a speculum examination

Consider the following:

Ultrasound → to exclude fibroids, adnexal pathology, endometriosis, or to assess an intrauterine contraceptive device
If at risk of STIs → high vaginal & endocervical swabs for STI screen
Pregnancy test → to exclude ectopic pregnancy

Primary dysmenorrhoea features	Secondary dysmenorrhoea features
Primary dysmenorrhoea is a diagnosis of exclusion, after secondary causes have been ruled out Onset: typically 6-12 months after menarche Pain related to menstruation Onset of pain shortly before menses Pain improves as menses progresses, lasting up to 72 hours No other gynaecological symptoms Non-gynaecological symptoms (e.g. nausea, vomiting, diarrhoea, fatigue, irritability, dizziness, bloating, headache, lower back pain, and emotional symptoms) may be present Normal pelvic examination	Onset: several years after painless periods Pain not consistently related to menstruation May persist after menstruation finishes, or Present throughout the cycle, but exacerbated by menstruation Presence of gynaecological symptoms Abnormal pelvic examination However, a normal examination does NOT exclude secondary dysmenorrhoea

Primary dysmenorrhoea features

Secondary dysmenorrhoea features

Primary dysmenorrhoea is a diagnosis of exclusion, after secondary causes have been ruled out

Onset: typically 6-12 months after menarche
Pain related to menstruation
- Onset of pain shortly before menses
- Pain improves as menses progresses, lasting up to 72 hours
No other gynaecological symptoms
Non-gynaecological symptoms (e.g. nausea, vomiting, diarrhoea, fatigue, irritability, dizziness, bloating, headache, lower back pain, and emotional symptoms) may be present
Normal pelvic examination

Onset: several years after painless periods
Pain not consistently related to menstruation
- May persist after menstruation finishes, or
- Present throughout the cycle, but exacerbated by menstruation
Presence of gynaecological symptoms
Abnormal pelvic examination
- However, a normal examination does NOT exclude secondary dysmenorrhoea

Management

Primary Dysmenorrhoea

Category	Recommended management
Conservative management	Consider: Local application of heat (e.g. hot water bottle, heat patch) TENS
Pharmacological management	Patient wishes to conceive: 1st line: NSAIDs 2nd line: paracetamol If NSAIDs alone not sufficient → add paracetamol If NSAIDs not tolerated / contraindicated → give paracetamol instead Patient does NOT wish to conceive: NSAIDs (if not tolerated / contraindicated → paracetamol), or COCP Offer a 3-6 month trial Alternative: POP, LNG-IUS, progesterone-only implant / injection If monotherapy is not sufficient → consider NSAIDs PLUS hormonal contraception