My doctor told me today I had an ovarian cyst explode on me. Can you tell me what exactly this means and why it happens?

-- Tanya

Well, "explode" is certainly dramatic and descriptive, but it doesn't really accurately explain what happens. You most likely had a cyst rupture. What this means is that a fluid-filled mass developed on your ovary; often this happens when an egg is not released at ovulation and the follicle -- the sac -- fills with more and more fluid and gets bigger and bigger. This may cause pain on one side of the pelvis. Eventually, the cyst can get so large that part of the wall weakens and fluid begins to leak out; that is, the cyst ruptures. It is similar to popping a water balloon. When this happens, the fluid may irritate the pelvic lining and cause pain, often severe. Most of the time the pain begins to gradually subside over the course of the next few days.

The reason your doctor ordered an ultrasound, or sonogram, was to look to see if there really was a cyst and to see if it had really ruptured. If the cyst had ruptured, there would be fluid in the pelvic cavity behind the uterus. If the cyst had not ruptured, it would look like a big black circle on the ultrasound screen.

If a cyst is present and is larger than 5 or 6cm, and if you are having a lot of pain, sometimes we will recommend a laparoscopy to remove the cyst. If it has ruptured, and your pain is getting better (as I suspect yours is or else you wouldn't be asking questions over the Internet!), then we usually just give pain medicine and watch to see what happens. If pain does not begin to improve within several hours, or if your blood count drops, then we have to do a laparoscopy to make sure you are not having any internal bleeding. Sometimes birth control pills are used to help decrease your chances of getting an ovarian cyst again. This is a common problem and can easily be taken care of by any gynecologist.