Several Causes of Hypothyroidism
- Agenesis and dysgenesis: Children and infants can show hypothyroidism as a consequence of thyroid gland absence or malformation and deficiency in thyroid hormone production.
- Antithyroid drugs: Propylthiouracil and methimazole are used to treat patients who have thyrotoxicosis and their over dosage can produce hypothyroidism.
Management of thyrotoxic women during pregnancy with these kinds of medications can originate hypothyroidism in the neonate. - Drugs: Amiodarone and lithium are some or the drugs that can provoke hypothyroidism.
Both drugs are extensively used in clinical practice.
Thyroid function analysis should be acquired previous to start some treatment with these agents and from time to time thereafter. - Infiltrative and Infectious Diseases: Primary hypothyroidism have infrequently been reported in patients who suffer of infiltrative and infectious diseases such as:
- Amyloid
- Cystinosis
- Fibrous thyroiditis of Riedel
- Hemochromatosis
- Leukemia
- Lymphoma
- Mycobacterium tuberculosis and Pneumocystis carinii infection
- Sarcoidosis
- Scleroderma
- Iodine: Iodine lack is the leading origin of hypothyroidism.
Patients frequently show big goiters.
Temporary hypothyroidism may also be an outcome from iodine overload.
This situation is called to as the Wolff-Chaikoff effect.
A good number of patients ultimately get away this consequence.
Great quantities of iodine are found in radiographic contrast substances. - Nuclear exposure: Besides to an augmented threat of papillary thyroid cancer, kids living in neighborhoods of radioactive fallout from the Chernobyl nuclear catastrophe have an elevated frequency of thyroid autoantibodies and may be at bigger menace of rising hypothyroidism.
- Resistance to thyroid hormone (also known as Refetoff Syndrome): is an atypical genetic disease caused by mutations in the tri-iodothyronine (T3) receptor gene.
The thyrotropin stimulating hormone (TSH) level is regularly normal.
Thyroxine (T4) and T3 amounts are increased.
Patients who show this problem are generally euthyroid and do not need thyroid hormone replacement. - Surgery and radioactive iodine: Thyroidectomy and radioactive iodine treatment of patients who have Graves' disease, toxic thyroid nodules, or toxic multinodular goiters are ordinary origins of hypothyroidism.
Post-ablative hypothyroidism extends some weeks following radioactive iodine treatment.
Partial thyroidectomy may leave enough thyroid tissue at the rear to avoid the patient from taking thyroid hormone replacement.
Cyclic surveillance of thyroid function analysis is essential after thyroidectomy and radioactive iodine treatment for premature discovery and therapy of hypothyroidism.
Hypothyroidism can happen after peripheral radiation of the head and neck and after whole-body radiation.
It typically lasts many years for hypothyroidism to expand in these conditions.
Since the rather high occurrence of hypothyroidism subsequent to head and neck irradiation, recipients of such treatment require episodic clinical and biochemical evaluation of their thyroid function.