Hyperthyroidism

Hyperthyroidism is characterized by increased thyroid hormone synthesis and secretion from the thyroid gland , whereas thyrotoxicosis refers to the clinical syndrome of excess circulating thyroid hormones irrespective of source

TSH low T4 high / normal T3 high / normal ( unless on T4 treatment ). Direct physiological effect of the excess hormone & ↑↑ catecholamine activity. Thyrotoxicosis often used interchangeably with hyperthyroidism , it can be defined as" excess thyroid hormone in the body, including exogenous intake of thyroid hormome preparations .Prevalence about 1 % to 2 % in women and 0.1 -0.2 % in men Happens in all ages 6 times more common in women

Subclinical hyperthyroidism- Low TSH but normal T4 and free T3 Possibly more prevalent than commonly believed- any symptoms of hyperthyroidism ? drugs ? Non-thyroidal illness ? -Repeat in 3-6 months time or earlier if elderly CV dis Non- thyroidal dis may have caused the initial abnormality.Persistent and unexplained - refer endocrinology

Two main causes of an overactive thyroid are Grave's disease - peak incidence age 30 Toxic multinodular goitre. Primary hyperthyroidism- increased secretion of thyroid hormones causes a negative feedback resulting in ↓↓ TSH levels Secondary hyperthyroidism- abnormality is at the level of...