Endometriosis is one of the most common gynecological disorders, affecting as many as one in 10 women of reproductive age. It is a chronic condition in which the tissue that forms the lining of the uterus, called endometrium, grows outside the uterine cavity on organs such as the ovaries, Fallopian tubes, bowels and bladder. In rare cases, tissue can even develop in the nose or lungs.

While most cases of endometriosis occur in women who are between 25 and 35 years of age, girls as young as 11 or 12 years old have been diagnosed with the disease.

“Adolescent girls are sometimes not diagnosed with endometriosis because they are thought to be too young to have the disease, or because they are thought to be exaggerating the regular pain from their periods,” says Rachael L. Polis, D.O., MPH, a pediatric and adolescent gynecologist.

A woman sheds her uterine lining each month throughout her menstrual cycle. When this lining grows outside the uterus however, the blood that’s shed can’t exit the body the same way it does during menstruation. Blood continues to thickens, breaks down and bleeds with each menstrual cycle, but remains trapped in a woman’s body.

This can cause a reaction in the immune system, which eventually produces scar tissue and adhesions inside the abdomen. That can cause pelvic tissue and organs to stick to each other.

Endometriosis is the leading cause of infertility.

Symptoms include excessive menstrual cramps felt in the abdomen or lower back, pain during intercourse, abnormal or heavy menstrual flow, fatigue, painful urination during menstrual periods and gastrointestinal problems, such as diarrhea, constipation or nausea.

“An adolescent might also have acyclic pain, meaning the pain is not just associated with their menstrual cycle”, says Polis. “Pain severity is not necessarily a reliable way to indicate how extensive a woman’s endometriosis is. Some women experience very little pain, but we may find they have very advanced endometriosis. Others may be in severe pain with a mild condition.”

Many women or teens don’t even know they have endometriosis and mistake their symptoms for regular period pain. “Unfortunately, there has been a reported two- to five-year delay in diagnosis among adolescent patients with endometriosis,” explains Polis. “Delays can result from visits with non-gynecologic specialists, misdiagnoses, normalization of symptoms, and a prolonged referral time to see a gynecologist.”

Diagnosis Through Laparoscopy

The only way for your doctor to make a definitive diagnosis of endometriosis is with a procedure called a laparoscopy. During this procedure, your doctor will insert use a long, thin viewing instrument through a small, surgical incision near your belly to get a look inside your abdomen. If you are diagnosed with endometriosis, your doctor can use a similar laparoscopic procedure to remove the tissue affected by the disease, depending on the severity of your condition.

There is currently no cure for endometriosis and doctors don’t know the cause. The condition can be treated with medication or surgery to keep it from getting worse. Hormone therapies such as birth control pills, progestin therapy and pain medications can help.

Lifestyle adjustments such as exercise, sleep and diet can also be important for easing pain associated with endometriosis.