An ovarian cyst is a fluid-filled sac or pocket that forms on or inside an ovary. There are different kinds of ovarian cysts. They can occur for various reasons, and they may need different treatments.
Cysts vary in size
An ovarian cyst can vary in size from half an inch to 4 inches, and sometimes even much larger. Small cysts less than 5 centimeters across are considered to be benign (non-cancerous).
In general, if an ovarian mass is over 5 centimeters across, it is considered dangerous and should be surgically removed.
Benign ovarian cysts are common - and may cause no symptoms
Having a benign ovarian cyst is very common, regardless of age, and for many women creates little or no discomfort or symptoms.
The most common symptom reported is pelvic pain, or pressure in your lower belly on the side of the cyst.
When symptoms are present
Other symptoms of ovarian cysts can include:
- Breast tenderness.
- Fullness or heaviness in the abdomen.
- Pain during sex.
- Pain during your period.
- Pain in the lower back or thighs.
- Trouble emptying your bladder completely.
- Weight gain.
Abnormal vaginal bleeding has been reported, but it is rare.
Be sure to consult with your doctor if you experience any of these symptoms.
Types and causes of ovarian cysts
Different types of ovarian cysts are due to different causes.
Functional ovarian cysts
The most common type of ovarian cyst is known as a functional ovarian cyst. A functional cyst is a result of the menstrual cycle, so can only occur if you are premenopausal (you have started your menstrual cycle, but haven’t gone through menopause). Functional cysts are often harmless and painless, and typically go away after two or three menstrual cycles.
There are two types of functional cysts:
Follicular cyst. Your ovaries grow cyst-like structures called follicles every month to produce hormones and release the egg. A follicle cyst happens when an egg isn’t released and it keeps growing inside the ovary.
Corpus luteum cyst. After an egg is released, the follicle develops into a structure called the corpus luteum. The corpus luteum produces estrogen and progesterone and then dissolves if pregnancy does not occur. A corpus luteal cyst happens when excess fluid builds up in the corpus luteum.
Other types of cysts
Dermoid cyst. Also known as teratomas, these cysts are typically benign (non-cancerous) tumors that develop from the primary oocytes, or the cells that give rise to eggs. A primary oocyte is a totipotent cell, meaning it can become any other type of cell. For this reason, these cysts may contain hair, skin, teeth, bone, or fat in them, because they form from embryonic cells.
These cysts are common in those of childbearing age, and are rarely cancerous.
Endometrioma. This cyst is filled with old blood and tissue that resembles the lining of the uterus. They are often called chocolate cysts because of the dark color of the fluid within them. They can happen in those with endometriosis.
Serous cystadenoma. A cystadenoma happens when a cyst grows on the surface of the ovary and is filled with a watery or mucous-like material.
Cysts can also be caused by:
- Noncancerous growths
- Polycystic ovary syndrome (PCOS)
- Severe pelvic infection
- Ovarian cancer (rare)
What are the complications of an ovarian cyst?
An ovarian cyst can sometimes break open (rupture), especially during strenuous exercise or sexual activity. A ruptured ovarian cyst may not cause any symptoms. Or it may cause sudden, sharp abdominal pain. A ruptured cyst can cause a lot of blood and fluid loss. This can lead to low blood pressure. In some cases of a cyst rupture, surgical removal may be needed.
Rarely, a dermoid cyst or cystadenoma can grow too large and push the ovary out of place, twisting the fallopian tube (ovarian torsion). Ovarian torsion can block normal blood supply to the ovary, leading to sudden pain and sometimes nausea and vomiting. Emergency surgery may be needed for an ovarian torsion diagnosis.
If you are experiencing severe abdominal or pelvic pain, or pain with fever or vomiting, it is imperative to seek immediate medical attention.
For postmenopausal women, pathological cysts (ovarian cysts that are not related to menstruation) increase the likelihood of developing an ovarian tumor.
Who is at risk of developing ovarian cysts?
Certain things might increase your risk of having ovarian cysts, including:
- Endometriosis. This condition causes the uterine lining to grow outside the uterus. Some of the tissue can attach to the outside of the ovary and form a growth.
- Having previous ovarian cysts. If you have had an ovarian cyst in the past, it increases the chance that you will have more.
- Hormonal problems. Use of fertility drugs that make you ovulate, such as clomiphene (Clomid).
- Polycystic ovary syndrome (PCOS). This condition causes multiple cysts to grow on the ovaries.
- Pregnancy. Some cysts that form during ovulation may stay on the ovary during pregnancy.
- Severe pelvic infections. Pelvic inflammatory disease, or STDs such as chlamydia, create infections in the pelvic area, making it more likely the infection will spread to the ovary and form an abscess.
Diagnosing ovarian cysts
Your primary care doctor, gynecologic oncologist, or an obstetrics and gynecology (OB/GYN) doctor may diagnose if you have one or more ovarian cysts.
Your doctor will ask about your medical history and your symptoms. You will also have a physical exam. This will likely include a pelvic exam, during which your doctor may feel for swelling on your ovary, which is often the first sign of a cyst.
If your doctor thinks you may have an ovarian cyst, you may need tests to help your doctor learn the type of cyst. Tests can also help rule out other problems, such as an ectopic pregnancy. The diagnostic tests may include:
- Biopsy. This is a test where a tiny piece of the ovary is taken and examined in a lab for ovarian cancer cells. The test might be done if an ultrasound shows suspect ovarian growths.
- Blood tests. These tests check for hormone problems and blood levels of a protein called cancer antigen 125 (CA 125), which can indicate endometriosis, PID, uterine fibroids, or cancer if these levels are elevated. A blood test is also used to determine if the cyst is bleeding.
- MRI. This procedure uses large magnets and a computer to create a detailed picture of the area.
- Pregnancy test. This is done to check if pregnancy may be the cause of a corpus luteum cyst.
- Ultrasound scan. In this test, a technician uses a wand-like device (transducer) to send and receive sound waves to view the size, shape, and location of the cyst. A pelvic ultrasound can also show if the growth is solid or filled with fluid. If the growth is solid, it indicates the presence of an adnexal mass (adnexal cyst), a growth that occurs in or near the uterus, ovaries, fallopian tubes, and connecting tissue.
Treating and managing ovarian cysts
Treatment for ovarian cysts depends on the type of cyst, your age, and your general health. You may be told to watch your symptoms over time (“watchful waiting”). An ovarian cyst will often go away with no treatment in a few weeks or months.
In some cases, you may need to have follow-up ultrasound tests to determine if your cyst has gone away or is not growing.
When surgery is indicated
If your ultrasound or blood tests show signs of ovarian cancer, your doctor may advise surgery to remove an enlarged cyst as well as part or all of your ovary.
Your doctor might also advise surgery if:
- Your cyst appears to be growing or is very large.
- Your cyst causes ongoing pressure or severe pain.
- You have endometriosis and want the cyst removed to help with fertility.
Can an ovarian cyst be prevented?
Although there is no way to fully prevent an ovarian cyst, regular pelvic exams will help your doctor identify any abnormalities as early as possible.
In some instances, if you have hormone issues, your doctor may advise taking birth control pills. Such medications stop the menstrual period altogether to ensure that problematic ovarian cysts cannot grow.
Taking antibiotics for a pelvic infection may decrease the likelihood it will spread and form a cyst.
How to manage an ovarian cyst
Work with your healthcare provider to find a treatment plan that makes sense for you. Keep all of your follow-up appointments.
Tell your doctor right away if you have sudden belly pain or other severe symptoms. These may be caused by a ruptured ovarian cyst.
National Library of Medicine. Ovarian Cyst (https://www.ncbi.nlm.nih.gov/books/NBK560541/)
The Office on Women’s Health (OWH). Ovarian cysts (https://www.womenshealth.gov/a-z-topics/ovarian-cysts)