Adolescent girls who fail to respond to medical management of menstrual problems may have underlying pathology such as endometriosis.

A total of 1,051 Australian high school students aged 15-19, average 16 years 10 months, completed a detailed menstrual questionnaire. Mean age at menarche was 12 years 9 months. In 15.5% menarche had occurred at or below the age of 11 and in 23.4% after the age of 13. Almost two thirds currently reported a regular cycle with a mean duration of menstruation of 5.9 days.

More than half (58%) experienced low back pain, 64% experienced headaches, 62% bloating, 62% aching pelvic pain, 60% appetite change and 65% feeling down. Nearly three quarters (71%) reported cramping pelvic pain and 78% feeling really tired.

Most girls, (93%) experienced menstrual pain and two thirds self-medicated with analgesics. Nearly a quarter (22%) used the combined oral contraceptive pill, 14% primarily to treat period pain. In 15% analgesics were ineffective. One quarter of girls reported missing school because of menstruation almost always because of pain. Severe menstrual pain was reported by 21% of the girls.

A highly significant association was found between the severity of menstrual pain and interference with life activities. These included interference with social, sporting and sexual function, school attendance, work as well as relationships with friends, family and partners. Overall 35% reported ‘problems with my periods'.

Atypical menstrual symptoms such as pain emptying bowels, passing wind, passing urine, pain with a full bladder and during sexual activity were reported in 9-19% of the students.

It is estimated that 10% of teenage girls have endometriosis. Despite this it takes on average 12 years for the diagnosis to be made if symptoms develop before the age of 20. But what distinguishes young women who may have endometriosis from those who do not?

The majority of girls had mildly painful periods that were managed with simple analgesics and experienced little interference with activities.

However, around a quarter experienced moderate or severe pain, multiple menstrual symptoms and significant interference with life activities. It is among these young women, many of whom will present to their GP because of their periods, that the possibility of endometriosis should be considered, especially in those with atypical menstrual symptoms and who respond poorly to analgesics.

Dr Chris Barclay