Weight Gain as a Symptom of Graves' Disease
Weight gain may occur in people with Graves' disease, which is a form of hyperthyroidism caused by an autoimmune disease. In many cases, weight gain happens after treatment begins, when thyroid hormone levels return closer to normal and metabolism slows. In Graves' disease, the immune system mistakenly attacks the thyroid gland, leading to an overproduction of thyroid hormone. While weight loss is more common in hyperthyroidism, some people with Graves' disease may experience weight gain.
One cause of weight gain in people with Graves’ disease is the result of treatment of the hyperthyroidism associated with Graves’ disease. High levels of thyroid hormone often result in weight loss. When treatment for Graves’ disease helps return thyroid hormone to normal levels, weight loss may stop and some people may start to gain weight.
Weight gain in people with Graves’ disease also may result from increased appetite. High levels of thyroid hormone may increase people’s appetite to keep up with increased metabolism. People who eat more calories than needed may gain weight.
When experiencing weight gain, it's important to consult with a healthcare professional for proper evaluation and guidance to avoid complications with Graves’ disease. In some people with Graves’ disease, weight gain is not concerning or is desirable, especially after weight loss with Graves’ disease. The healthcare provider can help assess the underlying cause of the weight gain and recommend appropriate actions or treatments if needed the individual situation.
High levels of thyroid hormone typically increase metabolism and may cause weight loss. When treatment helps bring thyroid hormone levels back to normal, metabolism slows, weight loss may stop, and some people may regain weight they previously lost.
Increased appetite can also contribute to weight gain. Hyperthyroidism may raise appetite to keep up with a faster metabolism, and if calorie intake remains elevated after treatment begins, excess calories may lead to weight gain.
Weight gain related to Graves’ disease treatment often occurs within the first several months after treatment begins, though it may continue for up to two years in some individuals. Research suggests that people who had more severe hyperthyroidism at diagnosis or who lost a significant amount of weight before treatment may be more likely to experience weight gain afterward.
The type of treatment used may also play a role, with some studies showing greater weight gain in people who develop hypothyroidism after treatment and require thyroid hormone replacement.
In some people with Graves’ disease, weight gain after treatment is expected and may not be a cause for concern, especially if weight was lost before diagnosis. However, rapid or ongoing weight gain, or weight gain accompanied by other symptoms, should be discussed with a healthcare professional.
A healthcare provider can help determine whether weight changes are related to treatment effects, thyroid hormone levels, or other factors, and whether adjustments to care are needed.