Out of the 2017 total, those in their 30s accounted for 48.3 percent of the total, trailed by those in their 40s at 36.9 percent.

The comparable figures for those in their 20s, 50s, 60s and teens were 10.8 percent, 6.3 percent, 0.4 percent and 0.1 percent, respectively.

The Health Insurance Review & Assessment Service also put the number of endometriosis patients at 94,857 in 2015, up from 53,000 in 2008.

Experts advised women to have regular medical checkups for the condition, which is hard to detect because pelvic pain usually comes together with cramps.

Pelvic pain is the typical symptom of endometriosis, together with infertility, as the disease involves tissues that normally grow inside the uterus growing outside it.

Medical experts said relieving stress and maintaining a healthy weight through regular exercises will help reduce endometriosis in women. (Yonhap)