Uterine fibroids are benign growths or tumours in the uterus. They are a common occurrence and can develop within and outside of the uterus. Made up of mostly of dense muscle, they can cause problems such as abdominal swelling, painful and extended menstruations, urinary problems, and complications to pregnancy. The growth of fibroids is linked to estrogen, the higher the estrogen level, the larger the fibroid. One or more fibroids can be present in the uterus at a time.