Simple goitre

Colloid goitre
Congenital hypothyroidism
The causes for simple goitres are: (1) Enlargement of thyroid gland is common during puberty and 2) pregnancy due to increased physiological demand. Some drugs like thioureas, thiocyanates, iodine, para aminosalicylic acid, lithium can also cause goiter on long term administration. Dyshormonogenetic goiter is caused by defective genes which prevent or decrease the synthesis of thyroid hormones due to biochemical defects. The final common pathway to goiter formation in each of these situation is due to hypersecretion of TSH which stimulates thyroid gland growth.
(E) Emanations of other problems