Adenomyosis: A Common Cause of Heavy and Painful Periods
Heavy periods are common, but they are not always “just one of those things.” One possible cause is adenomyosis, a condition that can also cause painful periods, pelvic discomfort and sometimes fertility problems.
Adenomyosis is benign, which means it is not cancer, but for some women its symptoms can have a major effect on everyday life.
What is adenomyosis?
The womb, or uterus, has an inner lining called the endometrium and a muscular wall called the myometrium.
In adenomyosis, tissue similar to the lining of the womb grows into the muscular wall of the uterus. This can make the womb thicker, enlarged and sometimes tender.
Adenomyosis is different from endometriosis. In endometriosis, similar tissue is found outside the womb. In adenomyosis, the tissue is found within the muscle of the womb itself.
How common is adenomyosis?
It is difficult to know exactly how common adenomyosis is.
Older studies often only diagnosed it after a hysterectomy, when the womb could be examined under a microscope. Today, ultrasound and MRI scans can identify adenomyosis without surgery.
Studies published in BJOG suggest that adenomyosis may affect roughly 9% to 30% of women, although the true figure is uncertain.
It is often diagnosed in women in their 30s and 40s, but it can also occur in younger women.
What symptoms can adenomyosis cause?
Some women with adenomyosis have no symptoms at all. Others may experience significant problems.
Heavy periods
One of the most common symptoms is heavy menstrual bleeding.
Periods may become heavier or last longer than usual. Over time, heavy bleeding can lead to iron deficiency or anaemia, causing symptoms such as tiredness, weakness, dizziness or shortness of breath.
Painful periods
Adenomyosis can cause severe period pain, also known as dysmenorrhoea.
The pain may gradually become worse over time and can sometimes start before the period begins.
Pelvic pain
Some women experience an ongoing aching or heavy feeling in the lower abdomen or pelvis, even when they are not having a period.
Pain during sex
Deep pain during sexual intercourse can occur, although this symptom can also be caused by other conditions such as endometriosis.
An enlarged or tender womb
The womb may become larger, softer or more tender than usual. Some women notice a feeling of pressure or heaviness in the lower abdomen.
Fertility problems
Adenomyosis has also been linked with difficulties becoming pregnant in some women, although many women with adenomyosis conceive naturally.
It can also occur alongside conditions such as fibroids and endometriosis.
How is adenomyosis diagnosed?
Adenomyosis was once difficult to diagnose without surgery. Today, imaging is usually enough to make the diagnosis.
Transvaginal ultrasound
A transvaginal ultrasound scan is usually the first imaging test used.
A small ultrasound probe is gently inserted into the vagina to obtain a detailed view of the womb.
Doctors may look for features such as:
- a bulky or rounded womb
- uneven thickening of the womb muscle
- small cysts within the muscle
- changes in the normal appearance of the uterine wall.
According to RCOG guidance, ultrasound can be very useful for diagnosing adenomyosis, particularly when performed by an experienced clinician.
MRI scan
An MRI scan can provide more detailed images of the womb.
It may be recommended when the ultrasound result is unclear, when doctors need to distinguish adenomyosis from fibroids, or when a procedure such as uterine artery embolisation is being considered.
Is laparoscopy needed?
Usually, no.
A laparoscopy is a key investigation for some women with suspected endometriosis, but adenomyosis is inside the muscle of the womb and cannot usually be seen during laparoscopy.
How is adenomyosis treated?
Treatment depends on several factors, including:
- how heavy your periods are
- how severe the pain is
- your age
- whether you would like to become pregnant
- whether you also have fibroids or endometriosis
- how much the symptoms are affecting your daily life.
Not every woman with adenomyosis needs treatment.
Medicines and hormonal treatments
Several treatments can help control heavy bleeding and pain.
Hormonal coil
A levonorgestrel-releasing intrauterine system, often known as a hormonal coil, may help reduce heavy bleeding and period pain.
It works by releasing a small amount of progestogen directly inside the womb.
Hormonal medicines
Other hormonal treatments, such as the combined contraceptive pill or progestogen-based treatments, may also help control bleeding and pain.
GnRH medicines
Some women with severe symptoms may be offered medicines called GnRH agonists.
These temporarily lower oestrogen levels and may reduce bleeding, pain and the size of the womb. However, symptoms can return after treatment stops, and these medicines are generally used for limited periods because of side effects.
Pain relief
Anti-inflammatory medicines can help with painful periods, although they do not treat the adenomyosis itself.
Uterine artery embolisation
Uterine artery embolisation, or UAE, is a minimally invasive treatment that reduces the blood supply to areas of adenomyosis.
It may be an option for some women who want to avoid major surgery.
RCOG-reviewed evidence found that around three-quarters of women experienced improvement in their symptoms following UAE.
More recent TOG evidence suggests that bleeding and pain can improve significantly after the procedure.
However, symptoms can return over time, and UAE is not suitable for everyone. Women who hope to become pregnant in the future should discuss the possible effects on fertility carefully with a specialist.
Surgery
Hysterectomy
A hysterectomy, which involves removing the womb, is the definitive treatment for adenomyosis.
It may be considered when symptoms are severe, other treatments have not worked, and a woman does not wish to become pregnant in the future.
The ovaries do not normally need to be removed simply because adenomyosis is present.
For some women with a small, localised area of adenomyosis, more conservative surgery may occasionally be considered, particularly when preserving the womb is important.
When should you seek medical advice?
Speak to your GP or gynaecologist if:
- your periods are becoming increasingly heavy
- your period pain is interfering with work, sleep or everyday activities
- you have persistent pelvic pain
- you feel unusually tired or breathless
- you are bleeding through pads or tampons very quickly
- you have concerns about fertility.
Heavy and painful periods should not automatically be accepted as normal.
The key message
Adenomyosis is a common but sometimes overlooked cause of heavy periods and severe menstrual pain.
It occurs when tissue similar to the lining of the womb grows within the muscular wall of the uterus.
The condition can usually be diagnosed using ultrasound, with MRI sometimes providing additional information.
Treatment ranges from pain relief and hormonal treatments to procedures such as uterine artery embolisation. For women with severe symptoms who have completed their families, hysterectomy provides definitive treatment.
Most importantly, treatment should be individualised. What is right for one woman may not be right for another, particularly where future pregnancy is important.
Sources
This article is based on guidance and evidence published by the Royal College of Obstetricians and Gynaecologists (RCOG), The Obstetrician & Gynaecologist (TOG) and BJOG: An International Journal of Obstetrics & Gynaecology.
This information is intended for general education and should not replace individual medical advice. If you are concerned about heavy bleeding, pelvic pain or painful periods, speak to a healthcare professional.