Subclinical hypothyroidism is one of the most common endocrinopathy. Diagnosis can be based on laboratory findings, ie, serum TSH levels with normal fT4 concentrations. Irregularities in hormonal imaging may be accompanied by clinical symptoms, including: weakness, poor cold tolerance, dry skin, and memory impairment. In some patients this condition can develop into overt manifestation of hypothyroidism. It is also possible to withdraw the disorder and return to normal thyroid function. Hypothyroidism can lead to the development of many diseases, including cardiovascular, as well as obstetric complications in pregnant women. Subclinical hypothyroidism can lead to some of these diseases. The potential impact of hypothyroidism on bone disease, infertility, metabolic syndrome, or renal disease is also investigated. It is important to know the potential complications of thyroid dysfunction, their early diagnosis and the implementation of levothyroxine therapy. Indications for treatment are determined individually. The decision to treat is affected by the TSH level, patients age, presence of antithyroid antibodies, clinical symptoms of hypothyroidism or planning to become pregnant.

Key words: subclinical hypothyroidism, cardiovascular diseases, levothyroxine therapy, pregnancy, metabolic disorders.