Complications

Complications of Graves' disease can include:

• Pregnancy issues. Possible complications of Graves' disease during pregnancy include miscarriage, preterm birth, fetal thyroid dysfunction, poor fetal growth, maternal heart failure and preeclampsia. Preeclampsia is a maternal condition that results in high blood pressure and other serious signs and symptoms.
• Heart disorders. If left untreated, Graves' disease can lead to heart rhythm disorders, changes in the structure and function of the heart muscles, and the inability of the heart to pump enough blood to the body (heart failure).

• Thyroid storm. A rare but life-threatening complication of Graves' disease is thyroid storm, also known as accelerated hyperthyroidism or thyrotoxic crisis. It's more likely when severe hyperthyroidism is untreated or treated inadequately.

  The sudden and drastic increase in thyroid hormones can produce many effects, including fever, sweating, vomiting, diarrhea, delirium, severe weakness, seizures, irregular heartbeat, yellow skin and eyes (jaundice), severe low blood pressure, and coma. Thyroid storm requires immediate emergency care.

• Brittle bones. Untreated hyperthyroidism also can lead to weak, brittle bones (osteoporosis). The strength of your bones depends, in part, on the amount of calcium and other minerals they contain. Too much thyroid hormone interferes with your body's ability to incorporate calcium into your bones.