The symptoms of endometriosis can vary. Some women are badly affected, while others might not have any noticeable symptoms.
The main symptoms of endometriosis are:
You may also have heavy periods. You might use lots of pads or tampons, or you may bleed through your clothes.
For some women, endometriosis can have a big impact on their life and may sometimes lead to feelings of depression.
See a GP if you have symptoms of endometriosis, especially if they're having a big impact on your life.
It may help to write down your symptoms before seeing a doctor.
Endometriosis UK has a pain and symptoms diary (PDF, 238kb) you can use.
It can be difficult to diagnose endometriosis because the symptoms can vary considerably, and many other conditions can cause similar symptoms.
A GP will ask about your symptoms, and may ask to examine your tummy and vagina.
They may recommend treatments if they think you have endometriosis.
If these do not help, they might refer you to a specialist called a gynaecologist for some further tests, such as an ultrasound scan or laparoscopy.
A laparoscopy is where a surgeon passes a thin tube through a small cut in your tummy so they can see any patches of endometriosis tissue.
This is the only way to be certain you have endometriosis.
There's currently no cure for endometriosis, but there are treatments that can help ease the symptoms.
Your doctor will discuss the options with you. Sometimes they may suggest not starting treatment immediately to see if your symptoms improve on their own.
One of the main complications of endometriosis is difficulty getting pregnant or not being able to get pregnant at all (infertility).
Surgery to remove endometriosis tissue can help improve your chances of getting pregnant, although there's no guarantee that you'll be able to get pregnant after treatment.
Surgery for endometriosis can also sometimes cause further problems, such as infections, bleeding or damage to affected organs.
If surgery is recommended for you, talk to your surgeon about the possible risks.
Endometriosis can be a difficult condition to deal with, both physically and emotionally.
As well as support from your doctor, you may find it helpful to contact a support group, such as Endometriosis UK, for information and advice.
In addition to detailed information about endometriosis, Endometriosis UK has a directory of local support groups, a helpline on 0808 808 2227, and an online community for women affected by the condition.
The cause of endometriosis is not known.
Several theories have been suggested, including:
But none of these theories fully explain why endometriosis happens.
It's likely the condition is caused by a combination of different factors.