People with silent endometriosis have tissue similar to the lining of the uterus growing in other areas but with none of the characteristic symptoms, such as pain.

A lack of symptoms can result in people not receiving a diagnosis. According to older data, though, between 20–25% of people with endometriosis do not have any overt symptoms.

This article will discuss further details about silent endometriosis and the diagnostic process, as well as the symptoms, causes, and treatments.

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Endometriosis occurs when tissue similar to the lining of the uterus grows in other parts of the body, such as the ovaries or fallopian tubes. This can cause pain, particularly before a period or during sex.

However, some people have no obvious symptoms of endometriosis. Informally, people refer to this as “silent” endometriosis.

According to research from 2010, silent endometriosis is not uncommon. Between 20–25% of people with the condition are asymptomatic.

People with silent endometriosis often receive no diagnosis, as doctors may not test for the condition unless a person has symptoms.

Silent endometriosis, by definition, causes no symptoms. A person may have some mild symptoms they attribute to other causes, though.

For example, a person may mistake mild pain or bloating near their period for premenstrual syndrome (PMS). Many people who menstruate experience PMS symptoms, and some of the symptoms overlap with endometriosis.

To recap, the symptoms of endometriosis can include:

Another symptom people may encounter is difficulty getting pregnant.

Doctors can only confirm endometriosis by carrying out a surgical procedure known as a laparoscopy. During this procedure, a surgeon creates a small incision in the abdomen and uses a thin device to look for endometrial tissue outside the uterus. They may also take a small amount of the tissue to examine.

Because this procedure is invasive, doctors may first suggest testing for other conditions to rule them out, or using medical imaging to identify larger growths or “frozen pelvis,” which is when the uterus is stuck in position by the excess growth of cells. Imaging may involve undergoing an ultrasound or MRI scan.

However, people with endometriosis can face barriers getting to this stage. Endometriosis is an underdiagnosed condition. A 2022 review of previous research notes several factors that contribute to this, including:

  • a lack of awareness about endometriosis
  • a lack of investment in endometriosis research
  • inconsistency in how doctors diagnose it
  • sexist attitudes toward women’s pain

It is the responsibility of governments, health organizations, and medical facilities to change this, but in the meantime, some patients may find they need to advocate for themselves or try different doctors to receive testing.

There are also endometriosis advocacy groups that may be able to provide support and resources, such as EndoFound and Endometriosis Association.

Researchers are not entirely sure why endometriosis occurs, but there are several theories. One of the most well-known is retrograde menstrual flow, which is when menstrual blood flows upward to the fallopian tubes.

The theory is that this could allow some of the uterine lining to grow in places where it should not be. However, retrograde menstrual flow is very common and affects most females. Only 10% ever develop endometriosis.

Another theory is that the condition may begin as a result of a bacterial infection. A translated study from Japan identified five species of bacteria that were present in significantly higher numbers in the uteruses of people with endometriosis.

The authors of the study theorize that a bacterial infection could cause endometritis, or uterine lining inflammation, that then triggers the growth of tissue.

More research on this is necessary. Other potential factors include:

  • Genetics: Endometriosis often occurs in multiple people in the same family, indicating that it may be inherited.
  • Hormonal: The hormone estrogen can cause endometrial tissue to grow and spread. It is possible that endometriosis may be connected to problems with high estrogen.
  • Immune system: If a person’s immune system is not functioning as it should, it may not be able to identify and destroy endometrial tissue growing in places other than the uterus. Certain immune disorders are more common in those who have endometriosis.
  • Surgery: When a person has abdominal surgery, it is possible that the surgery may unintentionally pick up and move endometrial tissue. This may happen during surgeries such as a C-section or hysterectomy.

If they have no symptoms and the growths are not interfering with their lives, a person with silent endometriosis may not require treatment. However, if a person develops symptoms or plans to have a baby in the future, they may want to pursue treatment. The options include:

  • Pain relief medication: In cases where a person is experiencing mild symptoms of pain, a doctor may suggest using over-the-counter pain relievers, such as ibuprofen (Advil).
  • Hormonal birth control: A doctor may recommend this option to those with endometriosis who are not trying to become pregnant. Options include birth control pills or shots as well as an intrauterine device that can lessen how often someone has a period or stop periods altogether.
  • Gonadotropin-releasing hormone (GnRH) agonist: This treatment can be helpful for those with endometriosis who do wish to become pregnant. This medication halts the production of the hormones responsible for ovulation that cause endometrial tissue to grow, resulting in temporary menopause. This can help improve a person’s chances of becoming pregnant after they stop taking the medication.
  • Surgery: Surgical treatment for endometriosis involves a laparoscopy, during which the surgeon removes the patches of endometriosis or scar tissue.

All forms of endometriosis, including silent endometriosis, can affect a person’s ability to get pregnant.

According to a 2022 review, between 35–50% of people with endometriosis have infertility. Research into why this is the case is still ongoing, but it may occur for several reasons, such as:

  • endometriosis affecting the ovaries and egg production
  • inflammation causing damage to sperm and eggs
  • blockages in the fallopian tubes that prevent sperm and eggs from moving through them
  • symptoms, such as pain, preventing regular sex

Older research has found that of all females who experience infertility, up to 50% have endometriosis.

Having endometriosis also increases a person’s chance of experiencing a pregnancy loss, or miscarriage, and raises the risk of ectopic pregnancy. This is when a pregnancy begins in the fallopian tubes instead of the uterus.

However, many people who have endometriosis become pregnant and give birth without medical assistance. There are also treatments available, such as laparoscopic surgery and GnRH agonists.

Anyone who has not been able to conceive after 1 year of having regular, unprotected sex should speak with a doctor about the possible causes.

Silent endometriosis is an asymptomatic form of endometriosis. Older data suggests that between 20–25% of people with endometriosis have this type. People may not realize they have the condition unless they have difficulties getting pregnant.

In order to confirm a diagnosis of endometriosis, a surgeon must perform a laparoscopy to identify endometrial tissue in the body. Treatments include medications and surgery. Some options can increase a person’s chances of becoming pregnant if they want to in the future.