The cause of an ovarian cyst depends on the type of ovarian cyst that forms. Functional cysts are the most common and there are three different types of these:

• Follicular cyst which is the most kind of functional ovarian cyst. The ovarian cyst cause here is when the follicle that harbours the egg in the ovary does not release the egg properly or does not shed its fluid after release. Fluid continues to be added and the cyst grows and grows, normally for between 4 and 6 weeks when it will disappear. Follicular cyst tend to be asymptomatic unless there are complications such as ruptures.
• Corpus luteum cysts are the less common variant of functional ovarian cysts. When an egg is released there is some tissue left behind, known as the corpus luteum. When this fills with fluid or blood a corpus luteum cyst is formed. These will grow for a few months and as with follicular cysts will usually be painless unless they become ruptured.
• Hemorrhagic cysts are cysts fill with blood when one of the small blood vessels of the cyst break. As with the other functional cysts these can rupture causing severe pain to the female patient.

Another type of ovarian cyst is called an ovarian dermoid cyst. These are cysts that are formed from the cells that make eggs in the ovaries. They tend to appear in younger women and children and can contain all kinds of tissue such as hair, bone, fat and teeth.

Endometrioid cysts are another type of ovarian cyst and are formed as part of the endometriosis condition. The ovarian cyst cause of endometrioid cysts is when the mucus memrane of the uterus grows in the ovaries where it shouldn't be.

Another type of ovarian cyst is the cystadenoma. These cysts are created from the cells that make up the outer part of the ovary. They fill up with a thick mucus type fluid and although they can grow to become very large, they are usually benign.

Another cause of ovarian cysts is Polycystic Ovary Syndrome (PCOS). This condition is characterized by the growth of numerous small, benign cysts in the ovaries. Although the exact cause of PCOS is not well known, it is thought that they develop due to ovulation problems caused by hormonal imbalances.

Risk Factors

We have covered the different types of ovarian cysts that you may get, and why they form. There are, however, certain risk factors that will make some women more likely to develop some type of ovarian cysts than others:

• Infertility
• Unusual timing of menstruation cycles
• A history of ovarian cyst development in the past
• Menstruation before the age of 11
• Hormonal imbalances
• Therapy for breast cancer such as tamoxifen.

Next: Ovarian Cyst Symptoms

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