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common characteristic of this disease, i.e., exophthalmos. Patients usually experience weight loss, heat intolerance, tachycardia, palpitations, proptosis, and diffuse
enlargement of thyroid gland. Another rare form of thyrotoxicosis is Apathetic thyrotoxicosis which only occurs in the elderly. There are no typical hyperthyroidism’s
symptoms in this condition. The patient is drowsy, experiences anesthetic effect,
progresses to goiter, and also experiences weight loss [37].
Hypothyroidism
Hypothyroidism is caused by a decrease in overall metabolism due to insufficient
thyroid hormone levels in the body. Hypothyroidism falls into two broad categories [38]:
Primary Hypothyroidism Primary hypothyroidism occurs due to insufficient hormones as a result of less hormonal secretion or destruction of thyroid tissue responsible for secretion.
Hashimoto’s Thyroiditis It is an autoimmune disorder and main cause of primary
hypothyroidism in the USA. In this condition, thyroid cells and related enzymes are
being attacked by the body’s own immune system leading to thyroid cells destruction and lessen the ability of gland to produce thyroid hormones [39].
Secondary Hypothyroidism It occurs as a result of hypothalamic disease or pituitary gland’s pathology leading to insufficient release of thyroid and secondary thyroid stimulating hormone, resulting in inadequate thyroid hormone level [40].
Signs and Symptoms
Hypothyroidism imparts damaging effects on various body systems, i.e., metabolism, cardiovascular, and nervous system. The patient’s skin in this condition is
cool, yellow, and dry. Patients often have thinning eyebrows, rough skin as well as
hair, significant intolerance to cold, and alterations in the nervous system, such as
ataxia, alterations in mental status, and prolonged relaxation of deep tendon reflexes.
A life-threatening condition called myxedema coma may occur as a result of chronic
and extreme hypothyroidism, which is characterized by hypoglycemia, hypotension, bradycardia, and low serum sodium (hyponatremia) [2].
Iodine Deficiency
Iodine deficiency is the most common cause of hypothyroidism in developing countries. Since iodine is crucial for the production of thyroid hormones, the disease
establishes itself as congenital hypothyroidism in infancy. Patients will experience
1 Physiology of Endocrine System and Related Metabolic Disorders
common characteristic of this disease, i.e., exophthalmos. Patients usually experience weight loss, heat intolerance, tachycardia, palpitations, proptosis, and diffuse
enlargement of thyroid gland. Another rare form of thyrotoxicosis is Apathetic thyrotoxicosis which only occurs in the elderly. There are no typical hyperthyroidism’s
symptoms in this condition. The patient is drowsy, experiences anesthetic effect,
progresses to goiter, and also experiences weight loss [37].
Hypothyroidism
Hypothyroidism is caused by a decrease in overall metabolism due to insufficient
thyroid hormone levels in the body. Hypothyroidism falls into two broad categories [38]:
Primary Hypothyroidism Primary hypothyroidism occurs due to insufficient hormones as a result of less hormonal secretion or destruction of thyroid tissue responsible for secretion.
Hashimoto’s Thyroiditis It is an autoimmune disorder and main cause of primary
hypothyroidism in the USA. In this condition, thyroid cells and related enzymes are
being attacked by the body’s own immune system leading to thyroid cells destruction and lessen the ability of gland to produce thyroid hormones [39].
Secondary Hypothyroidism It occurs as a result of hypothalamic disease or pituitary gland’s pathology leading to insufficient release of thyroid and secondary thyroid stimulating hormone, resulting in inadequate thyroid hormone level [40].
Signs and Symptoms
Hypothyroidism imparts damaging effects on various body systems, i.e., metabolism, cardiovascular, and nervous system. The patient’s skin in this condition is
cool, yellow, and dry. Patients often have thinning eyebrows, rough skin as well as
hair, significant intolerance to cold, and alterations in the nervous system, such as
ataxia, alterations in mental status, and prolonged relaxation of deep tendon reflexes.
A life-threatening condition called myxedema coma may occur as a result of chronic
and extreme hypothyroidism, which is characterized by hypoglycemia, hypotension, bradycardia, and low serum sodium (hyponatremia) [2].
Iodine Deficiency
Iodine deficiency is the most common cause of hypothyroidism in developing countries. Since iodine is crucial for the production of thyroid hormones, the disease
establishes itself as congenital hypothyroidism in infancy. Patients will experience
1 Physiology of Endocrine System and Related Metabolic Disorders