Fatigue is a symptom of endometriosis that may affect as many as 3 in 4 people with the condition. There are several reasons why endometriosis can make a person feel tired all the time.

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Endometriosis occurs when tissue resembling the lining of the uterus grows elsewhere in the body. When this endometrial-like tissue is present outside the uterus, a person has an endometriosis diagnosis.

Research shows that many people with the condition may feel excessively tired. In a 2019 study, 54–74% of women with endometriosis reported experiencing moderate-to-severe fatigue.

This article explores how endometriosis can cause fatigue and how this may impact people living with the condition.

Symptoms of endometriosis vary depending on where the endometrial-like tissue has grown.

Endometriosis has four stages: minimal, mild, moderate, and severe. Each stage describes how much endometrial-like tissue is present and whether it is embedded into an organ or is growing on the surface.

In addition, there is a scoring system based on the amount, location, and depth of the disease. Doctors divide the scores into 1–5, 6–15, 16–40, and more than 40.

The severity of a person’s symptoms does not always correspond to the stage or the severity of the disease overall.

Endometriosis may lead to fatigue in various ways. These include:

1. Inflammation

The most common way endometriosis causes fatigue is through the inflammation it creates in a person’s body.

When endometrial-like tissue grows outside of the uterus, the body launches an immune response to try to remove the tissue.

This can cause extreme pain but also chronic fatigue.

2. Chronic fatigue syndrome (CFS)

Some research has also linked endometriosis to CFS, which is a complex illness that also causes long-term fatigue. In a 2019 study, 1 in 3 women with CFS also had endometriosis.

Another 2022 study seems to confirm the high level of comorbidity between CFS and endometriosis.

However, because there is little formal research on endometriosis fatigue, it may be difficult to tell whether the gynecological condition is causing persistent tiredness or if a person also has CFS. Doctors need more research in this area.

3. Anemia

A common symptom of endometriosis is heavy menstrual bleeding.

Menstrual blood contains high levels of iron, and a person who regularly loses a lot of blood can develop anemia. This can cause a person to feel tired all the time.

4. Hypoglycemia

Hypoglycemia is low blood sugar, which can cause a person to feel shaky, faint, anxious, and fatigued.

In rare cases, it may occur with the condition.

5. Hypothyroidism

Hypothyroidism occurs when the thyroid gland does not produce enough of certain hormones. The condition can cause fatigue, joint pain, and weight gain.

Researchers do not yet understand the relationship between thyroid problems and endometriosis but agree that the two conditions often occur together.

6. Mood disorders

Mood disorders such as depression, stress, or emotional trauma can leave a person feeling extremely low on energy.

People living with endometriosis are at a higher risk of developing the disorder. This can be due to a hormonal imbalance caused by endometriosis or as a result of having to live with chronic pain over time.

According to research, 15% of endometriotic patients were also living with migraine and had a history of childhood abuse.

In addition, 20% of women living with endometriosis reported a history of sexual abuse, 44% reported emotional abuse, and 50% reported emotional neglect. These types of adverse experiences, as well as any existing physical comorbidities, can also cause mood disorders.

7. Unhealthful diet

The more chronic symptoms a person has, the more fatigue they may experience. Endometriosis symptoms can get worse when the body’s estrogen levels rise, such as when a person has a period.

However, symptoms can occur at any time during the menstrual cycle, so eating foods that are low in fat and high in fiber can help keep hormone levels balanced.

More broadly, a diet high in fat and sugar can take a toll on a person’s health and will often leave them feeling sluggish and tired, and a lack of nutrients that help the body to stay energized may also contribute to fatigue.

Research also shows that a diet low in fiber and high in saturated fat and sugar can interfere with a person’s sleep, causing them to be tired during the day.

8. Vitamin D deficiency

Research suggests that a lack of vitamin D has links to exhaustion and depression.

On the other hand, research also indicates that having more vitamin D may help reduce the symptoms of endometriosis. However, doctors need more research to verify the relationship between endometriosis and vitamin D.

9. Menopause

During menopause, falling levels of estrogen and progesterone can disrupt sleep and cause hot flashes.

However, in cases of endometriosis, people in menopause will usually begin to get relief from many of the other symptoms of the condition, such as pelvic pain. This is due to the fact that estrogen decreases when a person’s menstrual cycle stops.

Only 2–5% of people with endometriosis will still have symptoms after menopause. However, they may still experience menopause-related fatigue.

10. Lack of exercise

The evidence for the benefit of exercise in alleviating endometriosis symptoms is not conclusive.

However, since having chronic pain can lead to a sedentary lifestyle, this can make a person feel more tired. If possible, doing light exercise each day can help a person living with endometriosis boost energy levels.

This works because exercise helps the cells produce more fuel for the body. It can also increase a person’s oxygen circulation.

In addition, exercise can help relieve both pain and mood disorders, all of which may contribute to fatigue.

A person with fatigue feels extremely tired and weak. Their energy levels will be low.

People with endometriosis may feel especially fatigued around the time of their menstrual cycle.

Fatigue can have other symptoms, including:

  • muscle or joint aches and pains
  • headaches
  • sore glands that are not swollen
  • difficulty concentrating and confusion
  • insomnia
  • flu-like symptoms
  • dizziness
  • nausea
  • heart palpitations

When fatigue is severe, a person will often take long naps and feel faint when rising or moving too quickly.

Fatigue may have links to endometriosis in a variety of ways. A person with endometriosis who feels fatigued should consult a doctor to help determine the underlying cause.

Depending on the cause, a doctor may recommend a variety of treatments. In addition, changes to a person’s lifestyle and diet, as well as getting support for any mood disorders, may help increase a person’s energy.

Is there a relationship between endometriosis and adrenal fatigue?

Not all medical professionals agree that adrenal fatigue represents a specific condition. Those who do believe that it results from overwork of the adrenal glands. However, research does show that endometriosis has an association with high levels of stress, and stress may have a link to adrenal dysfunction.

What are other endometriosis symptoms?

The symptoms of endometriosis may include painful cramping, long and heavy periods, nausea and vomiting, and infertility. Learn more about endometriosis here.

How can I overcome fatigue from endometriosis?

Eating a healthful diet, taking supplements such as iron or vitamin D, exercising, and keeping a consistent sleep schedule may help reduce fatigue in people living with endometriosis.

In addition, talking with friends, meeting people through social networks or online forums, or seeing a therapist can prevent feelings of isolation, reduce the risk of developing a mood disorder, and provide valuable tips and advice that can help a person cope.

Learn more about endometriosis treatments here.