Mention the difference between hypothyroidism and hyperthyroidism.

(N/A) Hypothyroidism: This condition is caused by the under-secretion of thyroid hormones. In children,it leads to cretinism,characterized by retarded physical and mental growth,short limbs,a protruding tongue,and dry skin. In adults,it causes myxedema,which is more common in females and is characterized by an abnormal metabolic rate and rough,dry skin.
Hyperthyroidism: This condition is caused by the over-secretion of thyroid hormones ($T_3$ and $T_4$). It leads to Grave's disease,which includes symptoms like an increased metabolic rate,weight loss,and nervousness. Exophthalmic goitre (protrusion of eyeballs) is often observed in adults. Toxic goitre,also known as Plummer's disease,occurs due to the excessive production of thyroxine.