]> 2026-07-31T11:51:05+00:00 WBR0260 0 en Subclinical hypothyroidism '''Incorrect'''-Mildly elevated serum TSH levels and normal circulating thyroid hormone levels characterize subclinical hypothyroidism. Patients do not have clinical features of hypothyroidism. Primary hypothyroidism '''Incorrect'''-Low circulating levels of thyroid hormones with TSH levels more than 10 IU/L characterizes primary hypothyroidism. Central hypothyroidism '''Incorrect'''-Secondary and tertiary are central hypothyroidism. Low circulating thyroid hormone levels with low or inappropriate normal TSH levels characterize them. Sick euthyroid syndrome Generalized resistance to thyroid hormones '''Correct'''-Besides primary, secondary and tertiary hypothyroidism, rarely generalized resistance to thyroid hormones may cause hypothyroidism. Generalized resistance to thyroid hormones results from a receptor defect in the peripheral tissues. They usually present at an early age with growth and mental retardation, however patients with milder defects can present later in life. Elevated circulating thyroid hormone levels with normal or elevated TSH levels are characteristic. They present with hypothyroidism despite having elevated thyroid hormone levels. Internal medicine Vendhan Ramanujam A 30 year old male presents with fatigue, decreased appetite, weight gain, constipation and cold intolerance. He recalls no event of stress. He does not take any medications. He is a non-smoker and a non alcoholic. His pulse is 48/min and blood pressure is 146/90 mmHg. Physical examination reveals cold extremities, pale skin, coarse hair and brittle nails. There is delayed relaxation of deep tendon reflexes. The thyroid gland is normal on palpitation. Laboratory studies reveal increased serum free T3 and T4 but normal serum TSH level. Which is the most likely diagnosis? E Endocrine 2020-10-27T23:56:42Z 2459150.4977083 WBR0260