What dysmenorrhea is
Dysmenorrhea is the pain that accompanies menstruation. It is the commonest menstrual disorder: more than half of women who menstruate have pain for one to two days each month. The pain is usually described as cramping in the lower abdomen and can radiate to the lower back or the thighs.
Primary and secondary dysmenorrhea
This distinction is what determines the investigation and the treatment.
- Primary dysmenorrhea: the pain is due to the period itself and not to any underlying condition. It is caused by prostaglandins, substances produced in the endometrium that make the uterus contract. It usually begins shortly after the first periods of adolescence, appears just before or as the period starts, and settles within the first few days. In many women it lessens with age and after childbirth.
- Secondary dysmenorrhea: the pain is due to an underlying disorder of the reproductive system. It often appears later in life, starts a few days before the period, becomes worse as the period goes on and may not settle when it ends. Characteristically it tends to get worse over time rather than better.
Which conditions cause secondary dysmenorrhea
- Endometriosis: tissue similar to the lining of the uterus grows outside it and bleeds in step with hormonal changes, causing pain and adhesions.
- Adenomyosis: endometrial tissue grows within the muscular wall of the uterus.
- Fibroids, particularly those within the wall of the uterus.
- Pelvic inflammatory disease and adhesions following infection or surgery.
- Cervical stenosis or congenital abnormalities of the uterus.
How it is investigated
The investigation starts with the history: when the pain began, where it is, how it relates in time to the period, and how much it affects your daily life. A gynecological examination and an ultrasound scan follow. Where the findings suggest it, laparoscopy may be needed; this allows the pelvis to be inspected directly and, in the same operation, findings such as endometriosis to be treated.
How it is treated
Primary dysmenorrhea usually responds to non-steroidal anti-inflammatory drugs, which act precisely on the prostaglandins. They are most effective when taken at the first sign of pain rather than once it is established. They are not suitable for every woman, so taking them should be discussed with your doctor.
Hormonal contraceptives — the pill, the transdermal patch, the vaginal ring, the subdermal implant and the hormonal intrauterine device — also reduce the pain and are a good option when you want contraception at the same time.
Regular exercise, enough sleep, relaxation techniques and local heat also help. When the pain does not settle with medication, treatment turns to the cause: removing endometriotic deposits or fibroids and, in severe cases that have not responded to anything else, hysterectomy as a last resort.
When to see your doctor
Period pain is not something you simply have to put up with. Make an appointment if the pain stops you going to work or school, if it is getting worse over time, if it began or changed in character after the age of 25, if it is not relieved by ordinary painkillers, or if it comes with pain during sex, difficulty conceiving or heavy bleeding.