It’s easy to dismiss pelvic pain, especially when it occurs during your period. But if you experience it a lot, you just might be suffering from endometriosis—a condition where the tissue that lines the uterus also grows outside of it. This tissue can make its way to the ovaries, fallopian tubes, intestines and even creep onto, or into, other organs such as the brain. And if this isn’t terrifying enough, it can also involve a lot of pain and blood.

The most alarming thing, however, is that many women with the condition don’t even know that they have it.

“It’s thought that around one in 10 women may have endometriosis. However, it’s hard to know the exact percentage as many women who have it experience few or no symptoms. Other women experience symptoms, but don’t seek medical help,” says Professor Fong Yoke Fai, Senior Consultant and Head of Benign Gynaecology Division at the National University Hospital Women’s Centre.

Even if you suffer from the condition, you may be asymptomatic 

Pelvic pain is the most common symptom, but the other signs include menstrual cramps, pain during or after sex, and pain during urination and bowel movement. Another big symptom is spotting between periods or very heavy menstrual flows that require one to change their tampon or pad every hour for up to a day.

Because many women with endometriosis don’t experience symptoms, they don’t get themselves checked for it. This can become agonising as, left unchecked, it can lead to a whole host of complications. For instance, since the clump of tissue that has gone astray has no way of exiting the body, it becomes trapped and develops into a formation of  cysts. The condition can also cause internal bleeding, pelvic tissues and organs sticking together, and even infertility.

“Research in the US has shown that endometriosis may be found in 24 percent to 50 percent of women who experience infertility. Egg or embryo quality may also be affected in the inflammatory environment,” says Professor Fong.

If you don’t experience the symptoms but struggle with infertility or have a history of miscarriages, there could be cause for concern. After all, women with “silent endometriosis” usually only find out about their condition after undergoing abdominal surgery for an unrelated health issue.

There is no treatment available as of yet, but there are options for relief

In order to get a diagnosis, you will have to undergo a pelvic exam or ultrasound scan,, but these tests aren’t always conclusive.

“To be 100 percent certain, your doctor may refer you to a gynaecological surgeon for a surgical procedure called a laparoscopy,” adds Professor Fong. A laparoscopy involves the insertion of a special telescope into the abdomen through a small cut near the navel—it allows the surgeon to check your pelvic organs and extract tissue for examination.

While there is currently no cure for the condition, there are treatments that relieve the symptoms and help with infertility available: patients can undergo hormone therapy (like taking progestin-only pills) to slow down the growth of tissue or undergo surgery (like having the abnormal growths and scar tissues removed) to improve one’s chances of pregnancy.

Want to get yourself checked out? Don’t wait till it’s too late to schedule an appointment with your doctor—you really don’t want to be taking a chance.