The thyroid gland is a butterfly-shaped gland located in the front of the neck just above the trachea. It consists of two connected lobes. The thyroid follicle is the secretory unit thyroid.
Thyroid hormones are,
- Thyroxine/ Tetraiodothyronine
Functions of thyroid hormones
- Control the basal metabolic rate
- Enhance mitochondrial metabolism
- Stimulate neural development and normal growth
- Stimulate protein synthesis and carbohydrate metabolism
- Increase cholesterol and triglyceride production and breakdown
There are three types of thyroid disorders
- non-thyroidal illness
Signs and symptoms of hypothyroidism are,
- Weight gain
- Muscle weakness
- Dry skin
- Hair loss
Causes of hypothyroidism
- Autoimmune hypothyroidism – Thyroid illness is most commonly caused by this. Hashimoto thyroiditis is the primary condition of hypothyroidism. Thyroid follicular cells are destroyed as a result.
- Inborn errors in thyroid hormone biosynthesis
- Iodine deficiency or excess
- Drug-induced – Various drugs affect thyroid function
- Radiation treatment – Hypothyroidism is caused by surgical removal of the thyroid gland.
- Viral or bacterial thyroiditis
- Subclinical hypothyroidism
Untreated hypothyroidism can lead to these diseases.
Myxoedema -It is caused by an accumulation of hydrophilic mucopolysaccharides in the skin and other tissues. Cretinism – It is a severe thyroid hormone deficit in infants.
Hyperthyroidism is a hypermetabolic disorder induced by excessive thyroid hormone production. Thyrotoxicosis is overactivity of the thyroid gland resulting in high amounts of thyroid hormones in the circulation.
Sign and symptoms of hyperthyroidism
- Weight loss
- Excessive sweating
Causes of hyperthyroidism
- Autoimmune thyroid diseases – Graves disease-symptoms are bulging eyes, goiter, sweating – Hashitoxicosis -symptoms are fatigue, anxiety
- Toxic nodular/multinodular goiter
- hCG induced hyperthyroidism
Many disorders are associated with variation in the concentration of thyroid hormones in the absence of definable thyroid disease. non-thyroidal illness causes are acute and chronic illnesses(myocardial infarction, surgery, trauma) and starvation.