Causes of Hyperthyroidism

Excessive thyroid hormone secretion from the thyroid gland is called "hyperthyroidism".  For whatever reason, excessive thyroid hormone is called "thyrotoxicosis".  For example, thyroid hormone synthesis does not increase in Hashimoto's disease, thyroid cells are broken down and the produced hormones pass into the bloodstream and this condition causes hyperthyroidism. The name of this table is "thyrotoxicosis".


Causes of Hyperthyroidism

(These diseases will be detailedly explained in  “Toxic goitre” chapter)


Hyperthyroidism Signs

The levels of t T3 and T4 hormones are found to be high, TSH level is found to be low. The levels of T3 and T4 hormones are found to be normal and TSH level is found to be low in subclinical hyperthyroidism that does not cause clinical symptoms.  Anti TPO, anti Tg and in some patient TSH receptor antibodies are investigated in the diagnosis.

Besides thyroid hormones, thyroid scintigraphy and the uptake of the radioactive substance are examined in the diagnosis of hyperthyroidism.  The uptake is low in thyroiditis but it is higher in other hyperthyroid causes such as Basedow disease.

Hyperthyroidism signs are malaise, nervousness, palpitation, heat intolerance, weight loss, sweating, diarrhea, shortness of breath, weight loss despite the increased appetite, decrease in menstruation. In some of the patients, protruded eyeballs may be seen.


Hyperthyroidism treatment

The use of antithyroid drugs is the first treatment for hyperthyroidism. These drugs act by stopping the synthesis of thyroid hormones. Usually Metimazol is used. Propylthiouracil is used in some special cases and pregnants. Antithyroid drugs cannot be used for life due to their side effects. After 6 months-1 year of treatment, permanent treatment is planned for hyperthyroidism. Permanent treatment is  surgical or  radioactive iodine treatment according to the cause of hyperthyroidism.


Side effects of antithyroid drugs

Metimazol and propylthiouracil have very important side effects. Agranulocytosis, toxic hepatitis, jaundice, itchiness (pruritus), and joint pain are some of these side effects. During the use of drug, patients are warned about these side effects.

Patients are followed up by examining the liver enzymes and blood counts periodically. When the liver enzymes elevate and the number of neutrophils decreases below 1500, the drugs are discontinued. If sore throat and fever occur while the medications are being used, the drug should be discontinued immediately and the doctor who performs follow-up should be informed.