No one knows surely the actual causes of fibroids. Researchers have some theories but most likely fibroids are the result of many factors interacting with each other. These factors could be hormonal, running in families, environmental or a combination of all these because no one knows what the actual cause is. Even we do not know what causes them to grow or shrink. Fibroids are always almost begin and they rarely turn into cancer. Fibroids are named depending upon where they lie. Out of all fibroids subucous fibroids are the least common (5% of all fibroids), they disturb the shape of the uterus and this one is the type most likely to cause fertility problem. Most fibroids do not cause any symptoms but some women with fibroids can have heavy bleeding between periods, feeling of fullness in the pelvic area, increased urination, pain during sexual intercourse, lower back pain, reproductive problems such as infertility and miscarriage.