Hyperthyroidism is the excessive secretion of hormones by the thyroid gland. This increase causes an increase in metabolism. The symptoms of hyperthyroidism are numerous. Among them are heart signs with tachycardia in particular, digestive disorders with weight loss despite adequate food intake and diarrhea, mood disorders or restlessness, tremors, increased sweating and temperature with muscle wasting. It can be due to an autoimmune thyroid disease, Graves' disease, often an overdose of iodine found in medication, a thyroid tumor, or an early stage of inflammation of the thyroid. When in doubt, the TSH level can confirm the diagnosis by the decrease of this hormone. Indeed, this condition is not treated with the thyroid hormones themselves, called T3 and T4, which would then be increased, but with the hormone to stimulate the thyroid because this treatment is more sensitive .