What is endometriosis? Endometriosis (say "en-doh-mee-tree-OH-
sus") is a problem many women have during their childbearing
years. It means that a type of tissue that lines your uterus is
also growing outside your uterus. This does not always cause
symptoms. And it usually isn't dangerous. But it can cause pain
and other problems. The clumps of tissue that grow outside your
uterus are called implants. They usually grow on the ovaries,
the fallopian tubes, the outer wall of the uterus, the
intestines, or other organs in the belly. In rare cases they
spread to areas beyond the belly. How does endometriosis cause
problems? Your uterus is lined with a type of tissue called
Reference endometrium Opens New Window (say "en-doh-MEE-tree-
um"). Each month, your body releases hormones that cause the
endometrium to thicken and get ready for an egg. If you get
pregnant, the fertilized egg attaches to the endometrium and
starts to grow. If you do not get pregnant, the endometrium
breaks down, and your body sheds it as blood