Everything to Know About the Chocolate Cyst

A chocolate cyst, medically known as an ovarian endometrioma, is a type of ovarian cyst filled with old, dark blood. This gives the cyst a rich, chocolate-like appearance, which is how it gets its name.

To understand chocolate cysts, it is helpful to talk first about endometriosis. This is a chronic condition where tissue similar to the lining of the uterus starts to grow outside the uterus. It often causes significant pelvic pain and, for some women, can make it more challenging to get pregnant.

Endometriosis affects about one in 10 women and girls of reproductive age worldwide. Among those with endometriosis, 20% to 40% may develop chocolate cysts, making them a sign of a more advanced or severe form of the disease.

These cysts typically attach to the ovaries and can interfere with their function. In some cases, they can significantly disrupt ovulation and fertility, making it harder to conceive.

While chocolate cysts can be a tricky part of endometriosis, understanding them is the first step toward managing symptoms and protecting reproductive health.

The exact cause of chocolate cysts, or ovarian endometriomas, isn’t fully understood. However, one of the most widely accepted theories is something called retrograde menstruation.

This happens when menstrual blood flows backward through the fallopian tubes and into the pelvic cavity, rather than exiting the body as it normally would.

Some of this tissue can then attach to the ovaries. Once that tissue settles in, it behaves just like the lining of the uterus, thickening and bleeding with each menstrual cycle. But unlike the uterus, where blood has a way out, there's nowhere for this blood to go.

This leads to inflammation, buildup, and eventually the formation of a cyst filled with old blood. Over time, the trapped blood inside the cyst turns dark brown, giving it that characteristic ‘chocolate’ appearance. This is where the name chocolate cyst comes from.

Endometriosis itself is divided into stages based on how much the endometrial tissue has spread. Stages three and four are considered the most severe and are more likely to result in the development of chocolate cysts.

Ovaries are the most common place for these cysts to form, mainly because they produce a high amount of estrogen - a hormone that helps fuel the growth of endometrial tissue. Without treatment, endometriosis can worsen, increasing the chances of developing these cysts and possibly affecting fertility.

The symptoms of a chocolate cyst can be a bit tricky to spot because they often overlap with those of endometriosis. In fact, many people may not even realize they have a cyst until they experience noticeable pain or fertility issues.

Here are some of the most common signs to watch for:

• Pelvic pain between periods that doesn’t seem to have a clear cause

• Painful or heavy periods

• Back pain, especially during your cycle

• Pain during sex, which can be deep and persistent

• Irregular or heavy menstrual bleeding

• Digestive discomfort, including bloating, constipation, or nausea

• Painful bowel movements

• Blood in your urine (though this is less common)

Some people with chocolate cysts don’t experience any symptoms at all, while others may have pain severe enough to impact daily life. If you’re dealing with any of these issues, especially on a regular basis, it’s worth speaking with a healthcare provider to find out what’s going on.

Diagnosing a chocolate cyst usually starts with a physical exam and imaging tests like an ultrasound or an MRI. These tools can help your doctor get a good look at what’s going on inside your pelvis. However, to confirm for sure that it’s an endometrioma, your doctor may need to take a closer look or even remove the cyst entirely.

This is typically done through a procedure called laparoscopy. It’s a minimally invasive surgery where small cuts are made in your abdomen, and a tiny camera (called a laparoscope) is inserted.

This allows your surgeon to see the cyst clearly, take a tissue sample for testing (a biopsy), or sometimes remove the cyst altogether. The sample is then sent to a lab where a specialist examines it under a microscope to confirm the diagnosis.

While there’s no cure for endometriosis, there are several treatment options that can help manage the symptoms and improve quality of life. What’s best for you will depend on your symptoms, your age, and whether you’re trying to get pregnant.

Here are some common approaches:

• Watchful waiting: If symptoms are mild, your doctor might suggest simply monitoring the cyst with regular checkups.

• Medication: Hormonal therapies, pain relievers, or other medications may help relieve symptoms and slow the growth of cysts.

• Surgery: If the cysts are large (typically over four cm), causing significant pain, or interfering with fertility, surgery, often via laparoscopy, might be recommended to remove them.

The right treatment is deeply personal. It’s important to talk openly with your doctor about your symptoms and goals, so you can work together to create a plan that fits you best.

Let’s be real. Women are often taught to tough it out when it comes to pain, especially around their periods. But chronic or severe pelvic pain is not normal, and brushing it off can lead to delays in getting the care you need. When it comes to endometriosis and chocolate cysts, early diagnosis can truly change the course of someone’s life.

That’s why awareness matters. The more we talk about conditions like endometriosis, the better chance we have at catching it early, slowing its progression, and managing the long-term symptoms more effectively.

Understanding the signs, symptoms, and treatment options for chocolate cysts is a key step in navigating this often misunderstood condition. With the right care and a treatment plan tailored to your needs, you can find relief and improve your quality of life.

And don’t underestimate the power of small lifestyle shifts. Prioritizing sleep, reducing stress, and exploring supportive therapies like pelvic physiotherapy can all play a role in easing symptoms and supporting your overall well-being.

Endometriosis can be a tough journey, but you're not alone. Listen to your body, advocate for your health, and take steps, big or small, toward feeling better. You deserve care that works for you.

Q. What happens if you don’t remove an endometrioma?

A. If left untreated, an endometrioma can continue to grow, cause pain, and potentially damage the ovary. It may also affect fertility and increase the risk of complications like ovarian torsion or rupture.

Q. Can ovarian endometriomas grow back?

A. Yes, even after surgical removal, endometriomas can return—especially if the underlying endometriosis isn’t managed with ongoing treatment.

Q. How can I prevent getting an ovarian endometrioma?

A. There’s no guaranteed way to prevent them, but managing endometriosis with hormonal therapy, regular checkups, and healthy lifestyle habits may help reduce the risk.

Q. What is the difference between an ovarian cyst and an endometrioma?

A. An ovarian cyst is a fluid-filled sac that can develop for many reasons, often related to the menstrual cycle. An endometrioma is a specific type of cyst caused by endometriosis and is filled with old blood.

Q. Is endometrioma worse than endometriosis?

A. An endometrioma is actually a type of endometriosis, often associated with more advanced stages of the disease. It can be more serious due to its impact on fertility and ovarian function.