Thyroid hormones, thyroxine and triiodothyronine, affect the work of all organs and organ systems. Whether they are in excess or in deficit, they lead to significant disturbances in the homeostasis of the organism, changing first of all the metabolic processes and leading to significant clinical manifestations, primarily in the cardiovascular, but also in other organ systems. The imbalance of thyroid hormones also has oralmanifestations, which are often the reason why patients visit the dentist. However, what worries dentists the most is the possibility of acute decompensation of hyper or hypothyroidism, with the appearance of thyrotoxic storm or myxedema coma, which are life-threatening conditions. Therefore, a valid pre-procedural evaluation and preparation of patients with thyroid hormone function disorders for pre-planned dental interventions is of great importance. During dental procedures, it is necessary to adhere to recommendations regarding the choice of local anesthetics, hemostasis, drug interactions, the possibility of infection and minimizing stress, all in order to avoid acute decompensation of thyroid imbalance.