Could my IUD be causing me to have regular bouts of nausea?

Intrauterine devices (IUD) such as the Mirena have been a wonderful breakthrough in birth control. Like any device and like any medication, they do have side effects. Some of the symptoms that you have listed are on the side effect profile of levonorgestrel, the hormone that is released by the Mirena IUD. Of the issues that you have noted, only abdominal pain is listed with a significant frequency (12% of people with the IUD). Mood swings are not listed as a side effect, but depression is (< 6%). Nausea has occurred in some people, but the number of people that reported nausea with the IUD is probably the same as the number of people without the iUD (< 5%). Thus, statistically, your nausea at night, and mood swings could be do to the levonorgestrel are more likely to be do to something else. I suggest that you schedule an appointment with the OBGYN or primary care physician that placed you IUD. Explain your symptoms in detail to this doctor. He or she will likely also need to do a thorough abdominal and pelvic exam to make sure everything looks normal. After that, I think your doctor will be able to tell you what is causing these symptoms. Good luck.