The cause of period pain can either be primary or secondary.

Primary dysmenorrhea
Painful periods are usually a normal part of the menstruation process. Normally the muscular wall of the womb contracts at a continuous rate, usually mild enough to an extent that it cannot be felt. However, during a period, contractions occur at a more intense rate in order to allow the lining of the womb to shed away. Compression of the muscular wall can affect blood vessels and cause them to constrict, leading to a reduction in the amount of oxygen delivered to the area, which can cause certain pain-triggering chemicals to be released in the area.

Although there is no apparent reason, in certain women contractions can be greater and they experience severe period cramps and period pain. This is why in some cases; pain-relief medication such as Mefenamic Acid may be needed to assist the patient through there painful periods.

Secondary dysmenorrhea
Painful periods may also be caused by an underlying concern (secondary dysmenorrhea). Such cases will require referral to a GP for further investigation.

Underlying causes of secondary period pain include:

  • Pelvic inflammatory disease: infection of the womb, fallopian tubes or ovaries
  • Endometriosis: growth of cells in other parts of the body
  • Fibroids: non-cancerous tumour growth in the womb
  • Intrauterine device insertion: is a form of contraceptive that can cause period pain


Although all of our content is written and reviewed by healthcare professionals, it should not be substituted for or used as medical advice. If you have any questions about your health, please speak to your doctor.

Authored Dec 22, 2017 by Joseph Issac, MPharm
Reviewed Dec 04, 2018 by Prabjeet Saundh, MPharm