Although fibroids and endometriosis both affect the uterus and share similar symptoms, they’re two different conditions.

Fibroids and endometriosis are conditions that affect the uterus. Fibroids are tumors that grow from the uterine wall. Endometriosis is a condition where the inner lining of the uterus (endometrium) grows outside the uterus.

Although fibroids and endometriosis are two different conditions, they share similar symptoms: Both conditions can cause pelvic pain, heavy menstrual bleeding, and difficulties with fertility.

It’s possible to have both fibroids and endometriosis at the same time. In fact, one 2021 research review found that endometriosis is often comorbid with fibroids, meaning that people often have both conditions.

Fibroids

Fibroids are tumors that grow in or on the uterus. These tumors are typically not cancerous.

The symptoms of fibroids include:

It’s possible to have fibroids without experiencing any symptoms, especially if the tumor is small or if you’ve experienced menopause.

Endometriosis

Endometriosis is a condition where tissue similar to the lining of your uterus — the endometrium — grows outside your uterus.

The tissue could grow on your ovaries, bowel, and elsewhere in your pelvis, causing pain and gynecological symptoms.

The symptoms of endometriosis include:

  • difficulty getting pregnant
  • heavy menstrual bleeding or bleeding between periods
  • pain during penetrative sex
  • painful periods
  • painful bowel movements
  • pelvic and lower back pain

As with fibroids, it’s possible to have endometriosis while experiencing little to no symptoms.

Overlapping symptoms

Fibroids and endometriosis have some overlapping symptoms, including:

  • bleeding between periods
  • heavy menstrual bleeding
  • painful menstruation
  • pain in the pelvis and lower back
  • pain during penetrative sex
  • difficulty getting pregnant

Because there are many similar symptoms, it’s possible to think you have fibroids when you actually have endometriosis (or vice versa). A healthcare professional can accurately diagnose the cause of your symptoms.

Fibroids

It’s not entirely clear why fibroids develop. Genetics may play a role: You’re more likely to have fibroids if you have a relative who has had them.

Hormones may also contribute to the development of fibroids. Estrogen and progesterone, which help the uterus lining regenerate during the menstrual cycle, might also stimulate the growth of fibroids.

Endometriosis

There’s no scientific consensus on the cause of endometriosis, but there are several unproven theories regarding its cause.

One or more of the following factors could cause endometriosis:

  • genetics
  • hormones, which may turn the cells outside the uterus into endometrial cells
  • retrograde menstruation, which is when menstrual blood flows back into your fallopian tubes and pelvic cavity instead of exiting through the vagina
  • the lymphatic system, which may transport endometrial cells out of the uterus
  • toxins

You may be more likely to develop endometriosis if you:

  • start your period at an early age
  • start menopause at an older age
  • have short menstrual cycles
  • have a low body mass index (BMI)

Overlapping causes and risk factors

Although you can have fibroids and endometriosis together, there’s no scientific evidence to suggest that one may cause the other.

However, as a recent research review points out, fibroids and endometriosis share some potential causes: Genetics and hormone imbalances may play a role in developing each condition.

Both conditions might be more common among people who started menstruating early.

Fibroids

A gynecologist typically diagnoses fibroids. They might:

  • ask in detail about your personal and family medical history
  • conduct a pelvic exam, which is when they check the condition, size, and shape of your uterus
  • order imaging tests, such as an ultrasound, to help them visually identify fibroids
  • order a pelvic MRI, which produces images of your uterus and ovaries

If you have fibroid-like symptoms but your clinician can’t identify any fibroids, they might order further tests to help determine the underlying cause.

Endometriosis

Your clinician might:

  • ask in detail about your personal and family medical history
  • conduct a pelvic exam and inspect your cervix for scar tissue
  • use a transvaginal ultrasound or an abdominal ultrasound to look for signs of misplaced tissue
  • perform a minor surgical procedure known as laparoscopy, which is the only certain way to diagnose endometriosis

If your clinician identifies misplaced endometrial tissue during the laparoscopy, they can remove it in the same procedure.

Overlapping tools for diagnosis

Fibroids and endometriosis can be diagnosed using the same tools, usually by a gynecologist.

Tools like pelvic exams and ultrasounds can help medical professionals determine whether you have fibroids, endometriosis, or another condition.

It’s also possible to have both fibroids and endometriosis at the same time.

Fibroids

Your clinician might prescribe gonadotropin-releasing hormone (GnRH) agonists or GnRH antagonists, which can shrink fibroids. These can be available as injectable or oral medications.

They might also suggest birth control pills or an intrauterine device (IUD), which can reduce menstrual bleeding and pain.

Other treatment options include noninvasive and minimally invasive procedures, such as:

  • myolysis procedures, which involve using heat to destroy fibroids
  • cryomyolysis procedures, which involve using extreme cold to freeze fibroids
  • uterine fibroid embolization, a procedure where small particles are injected into the uterus to block the fibroids’ blood supply, causing them to shrink
  • forced ultrasound surgery, a noninvasive procedure where fibroids are destroyed by high frequency sound waves

In severe cases, you might need surgery.

Surgery could include a myomectomy. During this procedure, a surgeon makes an incision in your abdomen and removes the fibroids from your uterus. It can be done with a large incision or laparoscopically, which involves a few small incisions.

If the above treatments don’t work, a hysterectomy might be worth considering.

Endometriosis

Endometriosis is often treated with the following:

  • supplemental hormones, which can reduce the growth of out-of-place endometrial tissue
  • hormonal contraceptives, like birth control pills, patches, and vaginal rings, to reduce pain and prevent the growth of endometrial tissue
  • GnRH agonists and antagonists, which can block the production of estrogen and stop menstruation
  • danazol (Danocrine), which can stop menstruation and reduce endometriosis symptoms
  • a laparoscopy, a minimally invasive surgery to remove out-of-place tissue
  • a total hysterectomy (this is a last resort)

Consult with your doctor or another healthcare professional about the potential benefits and risks of each treatment option.

They can make a recommendation based on the severity of your condition, your unique medical history, and whether you’re planning to get pregnant.

Overlapping treatment options

If you have both fibroids and endometriosis, certain treatments can be used to address both. These include:

  • hormonal contraceptives
  • GnRH agonists and antagonists
  • surgery

Fibroids and endometriosis often cause painful period cramps. Some home remedies can help relieve them, like:

Your healthcare professional might also recommend some lifestyle strategies to support your body, such as:

Endometriosis and fibroids can result in painful, uncomfortable symptoms. However, with treatment, it’s possible to reduce your discomfort and manage flare-ups.

Although endometriosis and fibroids can affect fertility, it’s still possible to get pregnant and have children. Speak with a healthcare professional about potential treatment options.

Sian Ferguson is a freelance health and cannabis writer based in Cape Town, South Africa. She’s passionate about empowering readers to take care of their mental and physical health through science-based, empathetically delivered information.