What is Hypothyroidism?
Hypothyroidism is a condition where structural or functional abnormalities lead to the insufficient synthesis of thyroid hormone. Hypothyroidism is more prevalent in women than in men; in the United States, the incidence is rising significantly in people ages 40 to 50. Hypothyroidism results from inadequate production of thyroid hormone, usually because of dysfunction of the thyroid gland due to surgery (thyroidectomy), radiation therapy, inflammation, chronic autoimmune thyroiditis (Hashimoto’s disease), or, rarely, conditions such as amyloidosis and sarcoidosis.
Types of Hypothyroidism
1. Cretinism in small children.
2. Myxedema in adults.
Causes of Hypothyroidism
1. Causes in the thyroid
a. Congenital defect/hereditary.
b. Unknown.
c. Post-surgery/radiotherapy.
d. Iodine deficiency.
e. Drug-induced.
2. Causes above the thyroid
a. Pituitary gland.
b. Hypothalamus.
3. Chronic inflammation of the thyroid.
It may also result from pituitary failure to produce thyroid-stimulating hormone (TSH), hypothalamic failure to produce a thyrotropin-releasing hormone, inborn errors of thyroid hormone synthesis, inability to synthesize thyroid hormone because of iodine deficiency (usually dietary), or the use of antithyroid medications such as propylthiouracil.
Clinical Features of Hypothyroidism
1. Cretinism in children: Generally manifested at birth but becomes evident within several months. There is long-term physiological jaundice, a hoarse cry, constipation, excessive sleepiness and feeding difficulties, delayed milestones. The physical characteristics of the cretin include a short stature, coarse features with protruding tongue, broad flat nose, widely set eyes, sparse hair, dry skin, protuberant abdomen with an umbilical hernia, impaired mental development and delayed dentition.
2. Adults: Nonspecificslow onset, lethargy, constipation, cold intolerance, stiffness, cramps, excessive menstruation. These are early signs.
Symptoms of Hypothyroidism
Late signs: Intellectual and muscle activity slows down, appetite decreases, weight increases, hair becomes dry, sparse and tends to fall out, skin becomes dry, the voice becomes deep and hoarse, hearing decreases, excessive sleepiness and obstructed breathing. Finally, Myxedema appears with a dull expressionless face, sparse hair, obesity, large tongue, pale cool skin that is rough.
Other signs: The heart gets enlarged due to the collection of fluids in the pericardium. Intestinal
obstruction may occur. Psychiatric symptoms appear and respiratory depression.
Management of Hypothyroidism
Replacement of thyroxin by a physician e.g. Thyrox.