Causes of ovarian cysts are many. During a normal menstrual cycle, the ovaries develop follicles each month. Estrogen and progesterone, two hormones which support pregnancy, are produced by these follicles. If a normal follicle continues growing for an extended period of time ovarian cysts can result.

Among ovarian cysts, follicular cysts are the most prevalent. They hardly ever produce any symptoms and usually resolve by themselves. They are usually harmless. Follicular ovarian cysts are usually caused when the pituitary gland hormones that stimulate egg release by the ovaries cause the follicle to swell instead. The enlarged follicle develops into a cyst.

Frequent causes of ovarian cysts occur when luteinizing hormones surge and an egg is release. When the egg is released, estrogen and progesterone are created by the ruptured follicle to prepare for the hypothetical conception. When the egg is sealed off, fluid accumulates inside the follicle and becomes what is called a corpus luteum. The corpus luteum will then expand and at that point becomes a cyst.

Corpus luteum cysts usually disappear on their own without treatment within a few weeks. In the meantime, however, it can grow to nearly 4 inches in diameter. It can also bleed into itself or twist the ovary. This can cause severe pelvic and abdominal pain. Moreover, if the corpus luteum cyst fills with blood, the cyst may rupture. This can cause internal bleeding and sudden, sharp pain.

The drug clomiphene citrate is a fertility drug that works to induce ovulation, and might in itself, be among the causes of ovarian cysts. Clomiphene citrate is in fact known to increase the risk of developing a corpus luteum cyst (which does not prevent or threaten pregnancy), and therefore probably causes other cysts as well.

Some cysts, such as hemorrhagic or endometrioid cysts develop like other cysts but are classified as such because they contain blood. This blood can result from injury or from the leakage of blood vessels into the egg sac. Causes of ovarian cysts forming in the endometrial tissue include bleeding and sloughing off of endometrial tissue that transplants itself in the ovaries. Blood eventually builds up, rupturing and causing pelvic pain.

Though it is not possible to completely prevent the causes of ovarian cysts, increasing exercise, controlling stress, improving the quality of your diet, and improving your health can help minimize the probability of the development of an ovarian cyst.