Cardiovascular consequences of thyroid diseases, their prevalence and treatment, 
particularly in cases with subclinical hyper- and hypothyroidism. The aim of the 
study was to draw attention to an association between the thyroid and 
cardiovascular diseases. The main topic was to lay emphasis on the importance of 
cardiovascular diseases caused by subclinical hyper- and hypothyroidism in the 
relation to the practice. The subclinical states precede the overt hyper- and 
hypothyroidism, and they are often present during their treatments. The changes 
in the levels of thyrotropin demonstrating subclinical thyroid diseases, could 
be detected in different non-thyroid diseases and resulted from the effect of 
some drugs. Particularly, the subclinical thyroid diseases become more frequent 
in older age. In the background of the high prevalences of atrial fibrillation, 
hypertension and psychosomatic events subclinical hyperthyroidism could be 
revealed. Subclinical hypothyroidism is characterized by an increased prevalence 
of elevated serum lipid levels, atherosclerosis, ischemic heart disease and 
hypertension often associating with the presence of anti-thyroid antibodies. It 
is important to reveal subclinical thyroid diseases in time for the effective 
treatment and for stopping of the cardiovascular damages before manifestations 
of cardiovascular diseases. The paper gives advice for the practice and the 
rational management. At the end, a survey of the association between thyroid and 
heart diseases in own department of internal medicine at the last three years is 
given.