They can cause pain. They also have poisen in them and if they rupture they will make you sick. Years ago I had them, while at a store shopping one of them did in fact burst and I got instantly sick. I vomited in the middle of the store and darn near passed out. The doctor can give you something to shrink them.
I had one almost 14 years ago. I had no pain associated with didn't even know I had but had to have a test for something else and they found it. They tried shrinking it with drugs for 3 months and it actually grew. I had mine removed along with the ovary it was on.
at 6:51 PM on Dec. 18, 2009
Yes and they can be very painful and make you nauseous. I was going to have surgery at Thanksgiving time to have mine removed but it burst on it's own.