Ovulation problems are upsetting, particularly because they can cause irregular menstruation and infertility. They are very rarely dangerous, however, and variations are normal. In most cases, the problem is caused by a hormonal imbalance that prevents ovulation. The imbalance is only rarely so severe that it has other dangerous effects on the body. However, other possible causes, such as polycystic ovary syndrome or diabetes, may cause farther-reaching problems and should be treated medically.