The secretions of the thyroid hormones are controlled by pituitary gland and hypothalamus which are parts of the brain. The common cause of hypothyroidism is thyroid disease. Certain medications also causes hypothyroidism like Amiodarone, drugs used for hyperthyroidism like propylthiouracil, methimazole, Litium.
The hypothyroidism occurring in infants and children is called Cretinism.
Myxedema coma is an acute medical emergency in which the thyroid hormones become extremely low and it is treated with intravenous thyroid hormone replacement and steroid medications.
Type |
Origin |
Explanation |
Primary |
Thyroid gland |
The most common types are Hashimoto’s thyroiditis, radioiodine therapy used for hyperthyroidism. |
Secondary |
Pituitary gland |
This type of hypothyroidism occurs if the pituitary gland does not produce enough of thyroid stimulating hormone which induces the thyroid gland to produce the thyroid hormones. It occurs in pituitary tumors, radiation and surgery |
Tertiary |
Hypothalamus |
It occurs if the hypothalamus fails to secret thyrotropin releasing hormone (TRH) which stimulates the pituitary gland to produce TSH. |
Thin and brittle hair.
Skin thickening
Serum prolactin will be increased.
Liver enzymes will be increased.
Hypothermia
Hypoglycemia
The Hypothyroidism is treated with Thyroid hormones. Levothyroxine is the most common medication used. It has to be taken lifelong and in the early morning.