Dysmenorrhoea or “painful periods” is the most common of all gynaecological symptoms. It is generally described as a crampy lower abdominal pain, which starts at the onset of menstruation. It can be classified as either:

Primary - menstrual pain occurring with no underlying pelvic pathology.

Secondary - menstrual pain that occurs with an associated pelvic pathology.

Risk Factors

The risk factors for primary dysmenorrhoea include:

Early menarche

Long menstrual phase

Heavy periods

Smoking

Nuliparity

Clinical Features

The typical description of dysmenorrhoea is lower abdominal or pelvic pain, which can radiate to lower back or anterior thigh. Pain is crampy in nature. It usually lasts for 48-72 hours around the menstrual period, and is characteristically worst at the onset of menses. The pain can be associated with other symptoms, such as; malaise, nausea, vomiting, diarrhoea, dizziness. Abdominal and pelvic examinations (including speculum examination of cervix) are performed but are usually unremarkable. Uterine tenderness may be present.

Investigations

No investigations are specific to primary dysmenorrhoea and therefore the work up is focused on ruling out underlying pathology.

Diagnostic Laparoscopy may be warranted to diagnose underline mild Endometriosis as a cause for Dysmenorrhea.

If the patient is at high risk of a sexually transmitted infection, then a high vaginal swab and endocervical swabs are indicated to screen for underlying infection.

If on examination a pelvic mass is palpated, a transvaginal ultrasound scan (TVS) should be performed to investigate further.

Lifestyle Changes

Stop smoking (there is a clear relationship between smoking and dysmenorrhoea).

Pharmacological

Anagelsia (First line):

1. NSAIDs (ibuprofen, naproxen, mefenamic acid). They work by inhibiting the production of prostaglandins; which have been implicated in the pathogenesis of primary dysmenorrhoea.
2. And/or paracetamol

3-6 month trial of hormonal contraception (Second line):

1. Monophasic combined oral contraceptive pill is most commonly used first line.
2. Intrauterine system (e.g Mirena coil) may also be effective.

Non-Pharmacological

Summary

Primary dysmenorrhoea refers to menses pain in the absence of an underlying pelvic pathology.

Prostaglandins released stimulate myometrial contraction and spiral artery vasospasm causing ischaemia of the secretory layer of the endometrium.

It typically has a good response to COCP and NSAID therapy.