Fun and interesting facts about thyroid

In Switzerland in the 1880's Theodor Kocher demonstrated that total thyroidectomy caused hypothyroidism but thought initially that the symptoms were due to chronic air way obstruction. Kocher performed over 2000 thyroidectomies. 

He reported his early experience of thyroidectomy for Grave's disease which had at that time a mortality of 13%. Later in in 1883 his mortality for total thyroidectomy for Grave's fell to a remarkable 1%. It was not until 1888 that he realised that the symptoms of total thyroidectomy were due to lack of thyroid.

He then recommended as a treatment for total thyroidectomy "half a sheep's thyroid lightly fried and taken with current jelly once a week". The modern treatment of hypothyroidism was born. Kocher was awarded the Nobel Prize for Medicine in 1909.

The American surgeon William Halsted could trace accounts of only eight operations in which the scalpel was used between 1596 and 1800. During one of these procedures, described by Fabricius in 1646, the patient, a 10‐yr‐old girl, died on the table and the surgeon was gaoled!

Thyroid hormones affect function of virtually every organ system & every tissue in the body

When overactive, everything is turned up – feel hot (increase in metabolism), restless/anxious, hyperactive heart , respiratory rate increase & GI motility, secretion (causing diarrhoea) etc.

When underactive, everything is dialed down –

slow, cool, fatigue, constipation etc

Thyroid enlargement (goitre) can be present in hypothyroid, hyperthyroid or euthyroid state

Though T3 is the active form, T4 is the preferred hormone for treatment of hypothyroidism.

Long circulatory half life of T4 provides remarakable stability ensuring a steady supply of t3 once a therapeutic dose is established.

Shorter half life of T3 makes it less appropriate for long term use.

Also there is an additional disadvantage of bypassing regulatory mechanisms controlling T4 to T3