Thyroid disease has long been known to have a complex relationship with body weight and metabolism. Thyroid hormone regulates metabolism in both humans and animals, and metabolism is measured by the Basal Metabolic Rate (BMR). Changes in BMR, either an increase or decrease, affect the body's energy balance. Since thyroid hormones influence the metabolic rate, body weight can also change accordingly.
In hyperthyroidism, where thyroid hormone levels are high, the basal metabolic rate increases, leading to weight loss and a decrease in body weight. Factors controlling appetite, metabolism, and activity are complex, with thyroid hormone being just one factor in this system. However, the more severe the hyperthyroidism, the more significant the observed weight loss. Weight loss also occurs in other conditions where thyroid hormones are elevated, such as during the toxic phase of thyroiditis. When thyroid hormone levels are excessively high, hyperthyroidism can also increase appetite, and in some cases, patients may gain weight instead of losing it.
In hypothyroidism, thyroid hormone levels decrease, causing the metabolic rate to drop. With the body using less energy, fat accumulation increases, leading to a rise in body weight. However, the cause of weight gain in hypothyroidism is complex and not always related to excess fat accumulation. In individuals with hypothyroidism, much of the additional weight is due to the retention of salt and water.
Thyroid disease has long been known to have a complex relationship with body weight and metabolism. Thyroid hormone regulates metabolism in both humans and animals, and metabolism is measured by the Basal Metabolic Rate (BMR). Changes in BMR, either an increase or decrease, affect the body's energy balance. Since thyroid hormones influence the metabolic rate, body weight can also change accordingly.
In hyperthyroidism, where thyroid hormone levels are high, the basal metabolic rate increases, leading to weight loss and a decrease in body weight. Factors controlling appetite, metabolism, and activity are complex, with thyroid hormone being just one factor in this system. However, the more severe the hyperthyroidism, the more significant the observed weight loss. Weight loss also occurs in other conditions where thyroid hormones are elevated, such as during the toxic phase of thyroiditis. When thyroid hormone levels are excessively high, hyperthyroidism can also increase appetite, and in some cases, patients may gain weight instead of losing it.
In hypothyroidism, thyroid hormone levels decrease, causing the metabolic rate to drop. With the body using less energy, fat accumulation increases, leading to a rise in body weight. However, the cause of weight gain in hypothyroidism is complex and not always related to excess fat accumulation. In individuals with hypothyroidism, much of the additional weight is due to the retention of salt and water.
