Functional state of the thyroid gland in patients of the cardiology department of Ternopil University Hospital Department of Emergency Care in Internal Medicine, I. Horbachevsky Ternopil National Medical University Ternopil, Ukraine Corresponding authors: Ilunga Lynn Scott Kantalanga [email protected] 6th year medical student; Amoke Chiamaka Joyce [email protected] 6th year medical student Scientific Supervisor: Dr. Martynyuk Larysa Petrivna INTRODUCTION. Function and status of thyroid gland is tightly connected with cardiovascular system. On the one hand increase or decrease function of thyroid gland can lead to development of cardiological diseases such as arrythmia, hypertension, atherosclerosis etc. On the other hand, medication used in treatment of cardiologic problems can lead to thyroid dysfunction. AIM. To find frequency of thyroid dysfunction in Cardiology patients MATERIALS. A retrospective analysis of 319 case histories of inpatients undergoing cardiac care in January and February 2020 was conducted. For all patient was made general clinical, laboratory (including lipid profile) and instrumental examination, some patients were evaluated for thyroid function (TSH, T4-free, T3-free, peroxidase antibodies). None of them was taking thyrostatics or thyroid replacement hormone therapy in history. RESULTS. Thyroid function was determined in 102 (31,97%) patients with arrhythmia (23,5%), malignant hypertension (8,8%), and ineffectively corrected hyperlipidemia (67,6%). Dysfunction of thyroid gland was found in 14 patients (20,3%) with noncorrected hyperlipidemia. Thyroid dysfunction was more prevalent in female. Subclinical hyperthyroidism was seen in 9 (64,28%) patients, clinical hypothyroidism was found in 4 (28,57%) person, subclinical thyrotoxicosis was seen in 1 (7,1%) patient. Elevated cholesterol levels in patients with subclinical hypothyroidism were presented by researchers in by Korean journal of Internal Medicine also. CONCLUSIONS. 1. 20,3% of patients with noncorrected hyperlipidemia in the cardiology department had thyroid dysfunction, with clinical or subclinical hypothyroidism predominating. 2. Determination of thyroid function is necessary in case of ineffective treatment of hyperlipidemia in order to presumably prescribe thyroid hormone replacement therapy.