Which is more dangerous? Graves’ disease or Hashimoto’s disease?

Graves’ disease is by far the more dangerous of these two autoimmune thyroid disorders. Overproduction of thyroid hormones can lead to thyrotoxicosis, a condition associated with excess thyroid hormones. Thyrotoxicosis is a medical emergency, causing rapid heart rate, abnormal heart rhythms, shortness of breath, insomnia, coma and ultimately death if not treated.^[1]

In contrast, although hypothyroidism associated with Hashimoto’s disease produces a number of unpleasant symptoms, these are not generally life-threatening and can be managed with normalization of thyroid hormones through thyroid hormone replacement therapy. Both Graves’ disease and Hashimoto’s disease are risk factors for other autoimmune diseases.^[2]