Uterine fibroids

Uterine fibroids are growths made from muscle and supporting tissue in the uterus. Their medical name is leiomyomas or myomas. They are benign, meaning they are not cancer.

Fibroids can be as small as a seed or large enough to change the shape of the uterus. You may have one fibroid or several. They can grow within the uterine wall, bulge into the space inside the uterus, or project from its outer surface.

Many fibroids cause no symptoms and are found during an examination or scan for another reason. Others cause heavy menstrual bleeding, pelvic pressure, pain, or problems related to pregnancy and fertility. Their effect is influenced by their size, number, and location.

Fibroids respond to the hormones estrogen and progesterone. They mainly occur during the reproductive years and often become smaller after menopause. A new or enlarging uterine mass after menopause should still be assessed rather than assumed to be a fibroid.

Fibroids are almost always non-cancerous. They do not appear to increase the risk of uterine cancer, and a fibroid does not usually turn into cancer.

You may have fibroids without noticing any symptoms. When symptoms occur, abnormal bleeding and pressure on nearby organs are common.

Possible symptoms include:

• Heavy or longer-than-usual periods
• Bleeding between periods
• Pelvic pressure, fullness, or pain
• Period pain that affects daily activities
• A swollen or enlarged abdomen
• Needing to urinate often or urgently
• Difficulty emptying the bladder
• Constipation or pressure in the rectum
• Pain during sex
• Lower back or leg discomfort

Heavy bleeding can lead to iron-deficiency anemia, meaning there are not enough healthy red blood cells because the body has lost iron. This may cause tiredness, weakness, headaches, dizziness, a racing heartbeat, or shortness of breath.

Fibroids can sometimes affect fertility or pregnancy, but many people with fibroids become pregnant without treatment and have healthy pregnancies. Fibroids that distort the inside of the uterus are more likely to affect implantation or contribute to miscarriage than fibroids on the outer surface.

Symptoms alone cannot confirm fibroids. Other conditions, including adenomyosis, endometriosis, pregnancy complications, and problems affecting the uterine lining, can cause similar symptoms.

The exact cause of uterine fibroids is not known. Each fibroid begins from a muscle cell in the uterus that grows into a firm mass.

Several factors appear to contribute:

• Hormones: Estrogen and progesterone can support fibroid growth.
• Genetic changes: Fibroid cells often have changes in their genetic material.
• Family history: Fibroids are more likely if a close relative has had them.
• Age: They are most often identified during the reproductive years.
• Ethnicity: Black people are more likely to develop fibroids, often at younger ages, and may have more severe symptoms.
• Body weight: A higher body weight is associated with a greater likelihood of fibroids, although people of any weight can develop them.

Starting periods at an early age may also be associated with fibroids. These are risk factors, not direct causes. Having one or more does not mean that you will develop fibroids.

A healthcare professional may suspect fibroids based on your bleeding pattern, pressure symptoms, pregnancy plans, and a pelvic examination. During the examination, the uterus may feel enlarged or irregular.

An ultrasound is usually the main test used to confirm fibroids. It uses sound waves to create images of the uterus. The scan may be performed across the abdomen or with a slim ultrasound probe placed in the vagina.

Other tests may be useful in certain situations:

• Blood tests can check for anemia and other causes of abnormal bleeding.
• MRI provides detailed images when treatment planning requires a clearer view of the fibroids.
• Saline infusion sonography uses sterile fluid during ultrasound to show the inside of the uterus more clearly.
• Hysteroscopy uses a thin camera passed through the cervix to examine the uterine cavity.

If you have unusual bleeding, particularly after menopause, tests may also be needed to examine the uterine lining. These tests are used to rule out other causes rather than to confirm an ordinary fibroid.

Fibroids that are not causing symptoms may not need treatment. Routine monitoring may be enough, especially if the fibroids are small or menopause is approaching.

Treatment is based on the symptoms that matter to you, the fibroids' location and size, your general health, and whether you want to become pregnant. No single option is best for everyone.

Medicines may reduce bleeding or pain but do not permanently remove fibroids. Options can include:

• Tranexamic acid to reduce menstrual bleeding
• Anti-inflammatory pain medicines for pain and bleeding
• Hormonal contraception to control periods
• A hormone-releasing intrauterine system, if the uterine cavity is suitable
• Medicines that temporarily reduce estrogen activity and shrink fibroids
• Iron treatment when blood loss has caused iron deficiency

Some hormone-suppressing medicines are used for a limited period or before a procedure because fibroids can grow again after treatment stops. Benefits and side effects should be discussed before starting them.

Procedures that preserve the uterus include:

• Myomectomy: Surgery to remove fibroids while leaving the uterus in place. The surgical approach depends on where the fibroids are located.
• Uterine artery embolization: Small particles block blood flow to the fibroids, causing them to shrink.
• Radiofrequency ablation: Heat energy destroys fibroid tissue.
• Focused ultrasound: Image-guided sound waves heat and damage selected fibroids without an incision.

Not every procedure is suitable if you hope to become pregnant. Myomectomy has the longest-established role when fibroid removal is needed to improve the uterine cavity, but its benefits depend on fibroid location and other fertility factors. Pregnancy after embolization or ablation requires an individual discussion because evidence is more limited.

A hysterectomy, which removes the uterus, is the only treatment that guarantees fibroids cannot return. It ends the ability to carry a pregnancy. The ovaries do not routinely need to be removed solely because of fibroids.

Endometrial ablation destroys the uterine lining to reduce bleeding. It does not remove fibroids within the uterine wall and is not intended for anyone planning a future pregnancy.

Most fibroids do not cause serious complications. Problems are more likely when bleeding is heavy, fibroids are large, or they distort the uterine cavity.

Possible complications include:

• Iron-deficiency anemia from ongoing blood loss
• Persistent pain or pressure affecting sleep and daily activities
• Difficulty emptying the bladder or, rarely, pressure on the urinary tract
• Fertility difficulties linked to certain fibroid locations
• Miscarriage or pregnancy complications in some cases
• Fibroid regrowth or development of new fibroids after uterus-preserving treatment

During pregnancy, fibroids may be associated with pain, an unusual fetal position, premature birth, placental problems, or a higher chance of cesarean birth. The level of risk is not the same for every pregnancy.

A fibroid can occasionally outgrow its blood supply and begin to break down, known as degeneration. This may cause significant pain, including during pregnancy. A fibroid attached by a narrow stalk can rarely twist and cause sudden pain.

There is no reliable way to prevent uterine fibroids. Their development involves hormones, genetics, and other factors that are not fully understood or controllable.

Maintaining a weight that is healthy for you may support overall health, but it does not guarantee that fibroids will be prevented or stop existing fibroids from growing. No food, supplement, or exercise program has been shown to eliminate fibroids.

If heavy periods are present, early assessment can help identify iron deficiency and reduce the effect of blood loss. This manages a possible complication rather than preventing the fibroids themselves.

Fibroids can remain unchanged, grow slowly, shrink, or cause symptoms that change over time. Growth is more common during the reproductive years and may occur during pregnancy. Many fibroids shrink after menopause as hormone levels fall, although this is not guaranteed.

If your symptoms are mild, you may only need routine follow-up. Keeping a record of bleeding, pain, bladder symptoms, and their effect on your activities can help show whether the condition is changing. Blood tests may be repeated if heavy bleeding continues.

Treatment can greatly improve bleeding and pressure symptoms, but outcomes differ by treatment. Medicines usually control symptoms only while they are being used. New fibroids can develop after myomectomy, and treated fibroids may not disappear completely after embolization or ablation. Fibroids cannot recur after hysterectomy because the uterus has been removed.

Most people with fibroids can continue their usual work, exercise, relationships, and family life. Period products, access to toilets, pain, fatigue, or worries about bleeding may still require practical planning. If symptoms are affecting sleep, work, sex, exercise, or emotional well-being, that is a reasonable reason to review treatment options.

Arrange a routine medical appointment if you have:

• Periods that are becoming heavier, longer, or more painful
• Bleeding between periods
• Pelvic pressure, persistent bloating, or an enlarging abdomen
• Frequent urination or constipation that does not settle
• Ongoing tiredness, weakness, or dizziness
• Difficulty becoming pregnant
• Fibroid symptoms that are no longer controlled by your current plan

Bleeding after menopause should be assessed promptly, even if you have previously been diagnosed with fibroids.

Seek urgent medical help for sudden, severe pelvic pain, especially if you are pregnant, have a fever, or are vomiting. Urgent assessment is also appropriate if heavy bleeding makes you light-headed or causes a rapid heartbeat.

Seek emergency help if bleeding is accompanied by fainting, severe weakness, chest pain, confusion, or difficulty breathing. These can be signs of substantial blood loss or severe anemia.

Can fibroids turn into cancer?

Fibroids are benign and do not usually turn into cancer. A rare uterine cancer called leiomyosarcoma can resemble a fibroid, but it is considered a separate condition. New growth or bleeding after menopause needs assessment.

Do fibroids go away on their own?

They may shrink, especially after menopause, but they do not always disappear. Before menopause, they may stay the same size or change over time. Symptoms can improve even when a fibroid remains visible on a scan.

Can I get pregnant if I have fibroids?

Yes. Many people with fibroids conceive and have healthy pregnancies. Fibroids are more likely to affect fertility when they change the shape of the uterine cavity or block a fallopian tube. Other causes of fertility difficulty may also need to be considered.

Does removing fibroids cure them?

Myomectomy removes the fibroids that are present, but new ones can develop later. Embolization and ablation shrink or destroy treated fibroids without preventing every future fibroid. Hysterectomy is the only treatment that prevents recurrence.

Can diet or supplements shrink fibroids?

No diet or supplement has been proven to remove fibroids. A balanced diet containing iron can support health when periods are heavy, but food alone may not correct anemia. Some supplements interact with medicines, so they should not replace medical assessment.

Do I need treatment if I have no symptoms?

Often, no immediate treatment is needed. Routine follow-up may be appropriate unless there is uncertainty about the diagnosis or the uterus changes after menopause. Treatment is usually directed at bleeding, pain, pressure, fertility concerns, or other meaningful effects on your life.