Patient information from BMJ

Endometriosis

Last published:Oct 10, 2022

Endometriosis happens when tissues that make up the lining of your womb spread and grow outside your womb. It can cause pain, and you may have difficulty getting pregnant. But there are treatments that can help.

What is endometriosis?

The lining of your womb is called the endometrium. Each month, the lining grows thicker as part of your monthly cycle, when your body makes more of the hormone oestrogen.

Sometimes tissue from the endometrium starts growing in other parts of the inside of your body. This is called endometriosis. No one knows for certain why it happens.

Endometriosis most often grows around:

• the ovaries

• the fallopian tubes

• the outside of your womb

• the lining of your pelvis, and

• the rectum and bladder, although these are less common.

The patches of endometriosis react to the different hormones your body makes during your monthly cycle. So they grow thicker each month, then break away and start to bleed (like the lining of your womb does when you have your period).

Your body slowly gets rid of the blood, but it can damage the surrounding area. You may get scars.

Women with endometriosis are more likely than other women to have difficulty in getting pregnant.

Your chance of getting endometriosis increases from when you first get your periods until you are about 40. After that your chance of getting endometriosis decreases.

What are the symptoms?

The two main symptoms of endometriosis are pain and difficulty getting pregnant. But some women don't have any symptoms at all.

Most women with endometriosis get pain in the pelvis. The pain can be severe or it may be a dull ache. Some women get the pain all the time. Others get pain only at certain times: for example:

• during sex

• when going to the toilet,

• or during their period.

Pain during your periods is very common. If you have endometriosis, you may find that the pain is continuous throughout your period, and gets worse over time.

Some women with endometriosis have other symptoms, such as:

• exhaustion and feeling generally unwell

• trouble sleeping, and

• depression.

Many women with endometriosis can get pregnant naturally. But about one-third of women who have been diagnosed with endometriosis need medical help to get pregnant.

For some women, having difficulty getting pregnant is when they first realise that they have endometriosis.

If you have symptoms that suggest that you might have endometriosis, your doctor might examine you, or send you for an ultrasound scan.

But the only way to be sure you that have endometriosis is to have a small operation called a laparoscopy. The surgeon looks inside your body with a tiny camera on a tube. If the results show endometriosis, you may be able to have surgical treatment at the same time.

Not everyone needs a laparoscopy. Your doctor might suggest treatments based on your symptoms.

What will happen to me?

If you don't get treatment, your endometriosis could get gradually worse, then get better when you go through the menopause. This happens to about half the women who get endometriosis.

Some women's symptoms improve after a time without treatments. This happens to about a third of women who have mild endometriosis.

Most women who have treatments get good relief from pain. Unfortunately, the pain often comes back sooner or later. But if your pain comes back, you can have more treatment.

For more information on treatments for endometriosis see our leaflet Endometriosis: what treatments work?