Ovarian cysts are a common gynecological condition that can affect women of all ages. These fluid-filled sacs that form on or within the ovaries can lead to a variety of symptoms and health concerns.

By understanding this condition more thoroughly, you'll be able to make informed decisions about your health and treatment options.

What Is an Ovarian Cyst? 

An ovarian cyst is a fluid-filled sac that forms either on or inside an ovary. Cysts that form on the ovaries are categorized into one of two types – functional or pathological. Functional ovarian cysts are common and connected to the menstrual cycle, whereas pathological ovarian cysts are not common and are unrelated to the menstrual cycle. 

What Causes Ovarian Cysts?

Ovarian cysts can develop for various reasons, and the specific cause can vary depending on the type of cyst. There are two primary types of ovarian cysts: functional cysts and pathological cysts.

Here's an overview of the common causes of each type:

Functional Cysts

  • Follicular Cysts: These are the most common type of functional cysts and form during the menstrual cycle. Each month, a woman's ovaries release an egg from a tiny sac called a follicle. If the follicle doesn't release the egg or doesn't dissolve after the egg is released, it can develop into a follicular cyst.
  • Corpus Luteum Cysts: After the egg is released from the follicle, the empty follicle sac usually transforms into a structure called the corpus luteum, which produces hormones. If the corpus luteum doesn't break down and fluid accumulates inside it, it can lead to the development of a corpus luteum cyst.

Functional cysts are generally benign and often resolve on their own within a few menstrual cycles. They are typically not associated with underlying health conditions.

Pathological Cysts

  • Endometriomas: These cysts are associated with endometriosis, a condition where tissue similar to the lining of the uterus grows outside the uterus. Endometriomas form when endometrial tissue attaches to the ovary and forms a cyst. These cysts can be painful and may affect fertility.
  • Dermoid Cysts: Dermoid cysts, also known as mature teratomas, are a type of ovarian cyst that can contain a variety of tissues, including hair, skin, teeth, and even bone. They form from germ cells and are typically benign but may require surgical removal.
  • Cystadenomas: These cysts develop from the cells on the surface of the ovary and can be filled with fluid (serous cystadenomas) or mucous-like material (mucinous cystadenomas). While often benign, they can become quite large and cause abdominal discomfort.
  • Polycystic Ovary Syndrome (PCOS): PCOS is a hormonal disorder that can lead to the development of multiple small cysts on the ovaries. These cysts are usually harmless but can contribute to irregular menstrual cycles and other PCOS-related symptoms.

The exact cause of pathological cysts, such as endometriomas, dermoid cysts, and cystadenomas, is not always clear. Genetic factors and hormonal imbalances may play a role in their development. PCOS, on the other hand, is a complex hormonal condition with a strong genetic component.

It's important to note that most ovarian cysts are not cancerous (malignant). However, in some cases, cysts can be cancerous, especially in postmenopausal women. If a healthcare provider suspects that a cyst may be cancerous, further tests and evaluations will be conducted to determine the appropriate course of action.

Regular gynecological check-ups, ultrasound examinations, and awareness of symptoms can help with the early detection and management of ovarian cysts, reducing the risk of complications and ensuring appropriate treatment if necessary.

Symptoms of Ovarian Cysts

When ovarian cysts do produce symptoms, they can vary in severity and type. It's important for women to be aware of potential ovarian cyst symptoms so they can seek medical attention if necessary. Here are some common symptoms associated with ovarian cysts:

  1. Pain or Discomfort: One of the most common symptoms of ovarian cysts is pelvic pain or discomfort. The pain can range from mild and dull to severe and sharp. It may be felt on one side of the pelvis or lower abdomen, and it can be constant or intermittent. Pain often occurs during menstruation or intercourse.
  2. Bloating: Women with ovarian cysts may experience abdominal bloating or a feeling of fullness in the lower abdomen. This can be accompanied by increased abdominal girth.
  3. Changes in Menstrual Patterns: Some women may notice changes in their menstrual cycle when they have ovarian cysts. This can include irregular periods, heavier or lighter bleeding, or missed periods. Ovarian cysts can disrupt the normal hormonal balance in the body, leading to these changes.
  4. Pelvic Pain During Intercourse: Pain or discomfort during sexual intercourse, known as dyspareunia, can be a symptom of ovarian cysts, especially if the cysts are large or located in a way that puts pressure on surrounding tissues.
  5. Frequent Urination: Large ovarian cysts can press against the bladder, causing a frequent need to urinate. This symptom can sometimes be mistaken for a urinary tract infection.
  6. Difficulty Emptying the Bladder or Bowels: In rare cases, very large ovarian cysts can exert pressure on the bladder or rectum, leading to difficulty emptying these organs. This can result in feelings of urgency, incomplete emptying, or constipation.
  7. Nausea and Vomiting: If an ovarian cyst becomes twisted or ruptures, it can cause severe abdominal pain, nausea, and vomiting. This is a medical emergency, and immediate medical attention is necessary.
  8. Pain on One Side: Depending on which ovary is affected, the pain or discomfort may be localized to the left or right side of the lower abdomen. Imaging tests such as ultrasounds can help identify the location and size of the cyst.

It's important to note that many ovarian cysts resolve on their own without treatment and may go unnoticed because they don't cause symptoms. However, if you experience any of the symptoms mentioned above, especially severe or sudden abdominal pain, it's essential to consult a healthcare provider. They can perform a physical examination, order imaging tests like ultrasounds, and recommend appropriate treatment options based on the size, type, and location of the cyst.

Main Types of Ovarian Cysts

Functional Ovarian Cysts Explained

Functional ovarian cysts occur each month during the menstrual cycle in the form of follicle cysts & corpus luteum cysts. As the menstrual cycle progresses, the pituitary gland produces Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH), which signal the ovaries when it is time to mature an egg and release it. 

When FSH signals the ovaries to mature an egg, a follicle (also referred to as a follicle cyst) is formed and the egg grows within. A surge of LH from the pituitary gland signals the follicle to rupture and release the egg when it is time for fertilization. 

What remains of the follicle after it has ruptured creates the corpus luteum, which is also referred to as a corpus luteum cyst. It predominantly produces progesterone to maintain the uterine lining and create an environment for a fetus to grow. When implantation does not occur, the corpus luteum breaks down and usually disappears within 10 days. 

On occasion, follicle cysts and corpus luteum cysts can increase in size, which is when many women typically experience the uncomfortable symptoms associated with ovarian cysts. 

What Causes Functional Ovarian Cysts to Get Bigger?

Sometimes, the ovary doesn’t ovulate and the follicle growing upon it doesn’t rupture to release an egg. Other times the follicle fails to discharge the fluid after the egg is released. In these cases, the follicle swells and a follicular cyst grows. 

Although the corpus luteum typically disappears within 10 days once the released egg is not fertilized, fluid can sometimes get trapped inside the sac and cause it to enlarge instead of break down.

The good news is that functional ovarian cysts are typically benign and disappear within 6-8 weeks without any treatment. Cysts under 5 centimeters normally don’t result in any symptoms and most women don’t even know they have one. Those that grow larger than 5 centimeters can cause symptoms such as abdominal & pelvic pain, as well as a feeling of bloating or pressure in the abdomen before they rupture. 

What Happens When Ovarian Cysts Persist?  

It is rare for functional ovarian cysts not to disappear within a few weeks, however, if uncomfortable symptoms persist, your healthcare practitioner will more than likely perform a transvaginal ultrasound to check the size and nature of the cyst. 

After 4-8 weeks, your healthcare practitioner will usually perform another ultrasound to check if the cyst has shrunk. If not, additional investigation is typically necessary and surgery may be suggested to remove the cyst for testing in a lab.

Pathological Ovarian Cysts Explained

Pathological ovarian cysts are not common, have nothing to do with the menstrual cycle, and typically develop due to an abnormal growth of cells. Symptoms of pathological ovarian cysts can include pelvic pain, discomfort during bowel movements, a frequent urge to pee, heavy menstrual bleeding, bloating, cramping, and difficulties getting pregnant. 

The three main types of pathological ovarian cysts include cystadenomas, dermoid cysts, and endometriomas. 

Cystadenomas are cysts that typically grow from a stalk that is attached to the outside of the ovaries. Normally filled with mucous or a watery-type fluid, cystadenomas are commonly non-cancerous but can grow quite large and block blood supply to the affected ovary. Cystadenomas usually require surgical removal. 

Dermoid cysts develop from the cells that make eggs in the ovaries. Because these types of cells can grow into any sort of tissue, dermoid cysts can contain fatty tissue, hair, skin, or even teeth. They can also grow quite large, twist the ovary in a painful way, and are therefore surgically removed once detected. 

Endometriomas are ovarian cysts that form due to endometriosis. This type of ovarian cyst is filled with endometrial-like fluid and can form on the ovary or inside the ovary. The fluid within the cyst is similar to menstrual blood and often turns brown over time. For this reason, endometriosis cysts, or endometriomas, are also referred to as ‘Chocolate Cysts’.    


Functional ovarian cysts are harmless, linked to the menstrual cycle, and typically disappear within a short time. Pathological ovarian cysts, like endometriomas, are not related to the menstrual cycle and form due to the abnormal growth of cells. For more information on causes and treatment options, read above.   

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