Hypothyroidism

Hyperthyroidism

It is the insufficient secretion of thyroid hormones causing cretinism
in children and myxoedema in adults

This syndrome arises as the body tissues and are exposed to excessive levels of T₃ and T₄ .

The main effects are due to increased metabolic rate. The gland enlarges and may develop single or multipie hormone secreting cells such as in Grave's disease and toxic nodular goitre

Cretinism is associated with the retarded mental and physical development. The child receives hormones from the mother before birth, so appears normal at first, but within a few weeks or months, it becomes evident that physical and mental development is retarded

Symptoms are disproportionately short limbs, a large protruding tongue, coarse dry skin, poor abdominal muscle tone and an umbilical harnia.

Exophthalmic goitre (Grave's disease) is the most common cause solid of thyrotoxicosis in adults. It affects, women more commonly than men. High levels of thyroxine are secreted, which are not subjected to the normal secretion of TRH from the hypothalamus and TSH from the anterior pituitary.

Exophthalamus (Protrusion of the eyeballs) due to the deposition of excess fat and fibrous tissue behind the eyes, is often present in Grave's disease. In severe cases, the eyelids may not completely cover the eyes during blinking of the conjuctiva and thus, predisposed to infection.

Myxoedema (Gull’s disease), conditions is common in adults and five times more common in females than in males.

It results in an abnormally low metabolic rate and lack of response to demand for increased energy, by muscles, during exercise.

Mental and physical processes becomes lower, skin become coarse, the hair lacks tustre, becomes brittle and tends to fall out.

Toxic nodular goitre (Plummer’s disease) is associated with excess secretion of thyroxine leading to the general effects of increased metabolic rate.