Although anyone who experiences a menstrual cycle can develop endometriosis, it’s more common among people in their 30s.

Endometriosis usually occurs when uterine-like tissue grows outside of the uterus. This can trap tissue and blood in places where they cannot exit the body, causing pain and other complications.

The cause of this process is still unclear, though experts do have a few theories.

Possible causes include:

  • Retrograde menstrual flow: Menstrual blood and tissue usually sheds and exits the body through the cervix. Sometimes, that blood can travel back up the fallopian tubes and dump into the pelvis.
  • Hormones: Estrogen may play a part in endometrial growth.
  • Surgery: During abdominal surgery, tissue may be unintentionally moved to other areas of the body by the instruments used for the procedure. Endometrial-like tissue has been found in abdominal scars.
  • Blood or lymphatic system transport: Tissue can travel through the blood or lymphatic system, spreading to other places in the body, similar to cancer cells.
  • Cell conversion: Other cells can decide they want to become endometrial cells and will start to grow endometrial-like tissue.

You may be more likely to develop endometriosis if you:

  • have a family history of the condition
  • have a health condition that affects your uterus
  • started menstruating before age 11
  • menstruate for more than 7 days at a time
  • heavy periods that last longer than 7 days

The early symptoms of endometriosis can be tricky to pinpoint as they can mimic other conditions. This can delay diagnosis and treatment.

Symptoms can include:

Fatigue, depression, and anxiety can all accompany the condition. The psychological effects of living with untreated endometriosis can have a huge effect on your quality of life.

A pelvic exam can help identify large cysts or scarring. Your clinician may request an ultrasound, MRI, or other imaging technique to look for lesions growing outside of the uterus.

The best way to diagnose endometriosis is a laparoscopy. This minimally invasive surgical procedure involves making small incisions along the abdomen and inserting a tiny tube and camera (laparoscope) to examine the tissue.

If your clinician finds tissues they suspect are endometriosis-related, they may take a sample (biopsy) for further investigation.

How common is endometriosis?

The World Health Organization estimates 10% of reproductive-age women and girls across the globe experience endometriosis.

Can you develop endometriosis suddenly or later in life?

Endometriosis is a progressive condition, which means it gets worse over time. Some people with endometriosis may not have symptoms at all, and others may only experience mild symptoms until later in life.

According to Endometriosis UK, it takes the average person 7.5 years to receive an endometriosis diagnosis.

Is it possible to prevent endometriosis?

It’s not currently possible to prevent endometriosis since its cause is still unknown.

Pain, excessive bleeding, and difficulty getting pregnant may be signs of endometriosis. Document your symptoms and consult with a healthcare professional about getting a proper diagnosis.

While there’s currently no cure for endometriosis, there are things that you can do to help manage your symptoms.

Catasha Gordon is a sexuality educator from Spencer, Oklahoma. She’s the owner and founder of Expression Over Repression, a company built around sexual expression and knowledge. You can typically find her creating sex education materials or building some kinky hardware in a fresh set of coffin nails. She enjoys catfish (tail on), gardening, eating off her husband’s plate, and Beyoncé. Follow her everywhere.