Hypothyroidism and hyperthyroidism sharon witemeyer md pediatrician introduction. American thyroid association further information further details on this and other thyroid related topics are available in the patient thyroid information section on the american thyroid association website at. Iodine deficiency is the most common cause of hypothyroidism in the world, autoimmune thyroid disorders afterwards then surgery. Leslie mendoza temple md, aboim, pooja saigal md, in integrative medicine fourth edition, 2018. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. In newborn infants cretinism in adolescents short stature, mental retardation, precocious puberty in adults symptoms largely reversible after therapy. Some degree of hypothyroidism is common in the elderly. Hypothyroidism endocrine and metabolic disorders merck.
Mechanisms related to the pathophysiology and management of central hypothyroidism. Hypothyroidism usually results from a disorder of the thyroid gland, in which case it is described as primary hypothyroidism. Hypothyroidism hypothyroidism is a clinical syndrome resulting from a deficiency of thyroid hormones. But in almost every patient, hypothyroidism can be completely controlled. Examples of thyroid disorders that give rise to hyperthyroidism include graves disease, plummer disease, and thyroiditis. People are hypothyroid if they have too little thyroid hormone in the blood. However, hypertension is not a typical sign of hypothyroidism. Hypothyroidism means that the thyroid gland cant make enough thyroid hormone to keep the body running normally. Foods to eat and avoid for hypothyroidism sehat the thyroid is an important endocrine gland located in the front part of the neck.
Thyroid hormone production is regulated by tsh, which is made by the pituitary gland in the brain. Other not so common causes of hypothyroidism include certain congenital diseases, pituitary disorder, pregnancy, or a. The condition is more common in women than in men, and its incidence increases with age. In response, tsh is released, which causes the thyroid to enlarge and trap iodine avidly. Accessed february 1, 2012, with additional information.
The thyroid produces and releases into the circulation at least two potent hormones, thyroxine t4 and triiodothyronine t3, which influence basal metabolic processes andor enhance oxygen consumption in nearly all body tissues. It is surrounded by a dense irregular collagenous connective tissue capsule, in which posteriorly the parathyroid glands are embedded. The hormones released by this gland control various important functions of the body. In patients with primary hypothyroidism, the thyroid stimulating hormone tsh level is elevated. Hypothyroidism can also be referred to as having a sluggish thyroid or a slow thyroid or low thyroid function but dont be fooled, these are all names for the same condition this condition should be differentiated from hyperthyroidism 3 which is the exact opposite condition hyperthyroidism refers to too much thyroid hormone floating around in your body which presents. The thyroid gland is found in the lower part of the throat and partially wraps around the upper windpipe trachea. The thyroid gland is composed of 2 lobes connected by an isthmus. Hypothyroidism is the insufficient synthesis of thyroid hormone necessary for metabolic processes throughout the body. After 1 to 2 months, this may develop into hypothyroidism. Most patients with nonhashimoto goiters are euthyroid or have hyperthyroidism, but goitrous hypothyroidism may occur in endemic goiter due to iodine deficiency. Hypothyroidism pathophysiology of the disease development the thyroid, a gland located in the front of the neck, plays a critical role in the bodys endocrine system, specifically in regards to cellular metabolismi. The thyroid is a small butterfly shaped gland that lies just under the skin below the adams apple in the neck.
Downloaded from the american family physician web site at. T 4 is produced only from the thyroid, whereas t 3 from the thyroid and from t 4 deiodination in extrathyroidal tissues. Hypothyroidism the journal of clinical endocrinology. The diagnosis is generally made when the pericardial disease is associated with an elevated thyroid stimulating hormone level, and other secondary causes are excluded. We read with interest the thorough seminar on hypothyroidism sept 23, 2017, p 1550,1 in which the authors implicate that hypothyroidism is a cause of hypertension. The most prevalent causes of hypothyroid disease include various autoimmune diseases, medication for hyperthyroid disease, and having had surgery on the thyroid. Anatomy, physiology and pathology of the thyroid gland. A low serum t4 without the expected increase in serum tsh raises the possibility of central hypothyroidism due to pituitary or hypothalamic pathology figure 1. This book aims to provide a general view of thyroid disorders, and a deeper explanation of hyperthyroidism and its complications and impact in health. It usually results from hashimoto thyroiditis and is often associated with a firm goiter or, later in the disease process, with a shrunken fibrotic thyroid with little or no function.
It may be transient, especially if the mother has tshr blocking antibodies or has received antithyroid drugs, but permanent hypothyroidism occurs in the majority. Pathophysiology and diagnosis of thyroid disease medicare. Hypothyroidism diet 10 things i wish my endocrinologist told me get the entire hypothyroidism revolution system today. A study published in the journal endocrinology and metabolism showed that women are two to five times more likely to develop subclinical hypothyroidism. Pdf on feb 8, 2012, irena kostic and others published causes of. Etiology, diagnosis, and management hypothyroidism is the result of inadequate production of thyroid hormone or inadequate action of thyroid hormone in target tissues. Ppt hypothyroidism powerpoint presentation free to. Hypothyroidism is a clinical syndrome in which the deficiency or absence of thyroid hormone slows bodily metabolic processes. You have hypothyroidism when you have high tsh and low t4 levels in your blood. Iodine deficiency decreases thyroid hormonogenesis.
Autoimmune hypothyroidism autoimmune hypothyroidism may be associated with a goiter hashimotos, or goitrous thyroiditis or, at the later stages of the disease, minimal residual thyroid tissue atrophic thyroiditis. Primary hypothyroidism is due to disease in the thyroid. Differentiate thyroid binding globulin deficiency from central hypothyroidism. Hypothyroidism is a common condition of thyroid hormone deficiency, which is readily diagnosed and managed but potentially fatal in severe cases if untreated. Pdf on feb 8, 2012, irena kostic and others published causes of hypothyroidism find, read and cite all the research you need on researchgate. But, the truth is that hypothyroidism causes a chain reaction of hormonal and functional problems throughout the body, so there are many secondary health problems and.
Primary hypothyroidism is the most frequently of all, 95%. The hypothalamus releases a hormone called thyrotropin releasing hormone trh, which sends a signal to the pituitary to release thyroid stimulating hormone. Thyroid physiology and laboratory evaluation of the thyroid. In conclusion, hypothyroidism induced pericardial diseases are. Hypothyroidism, also called underactive thyroid, is when the thyroid gland doesnt make enough thyroid hormones to meet your bodys needs. There is a generalized slowing down of metabolic processes.
In this part of the article, you will be able to access the pathophysiology of disease 7th edition pdf almost instantly using our direct links mentioned at the end of this article. In order to ensure faster downloads and user safety, we have uploaded this. Pathophysiology of hyperthyroidism free download as powerpoint presentation. The 2nd most common cause is posttherapeutic hypothyroidism. Hypothyroidism, multinodular goiter, hyperthyroidism and thyroid cancer are only few of the several implications that the thyroid disorders have in health. The highest prevalence of primary hypothyroidism is hypothyroidism, which can develop as a result of the destruction of the thyroid gland. Blood tests can measure your levels of thyroid stimulating hormone tsh and thyroid hormone t4. Symptoms of hypothyroidism include fatigue, weight gain, alteration in cognition, infertility, and menstrual abnormalities.
Thyroid stimulating hormone tshinsulinlike growth factor 1 igf1 receptor crosstalk in human cells christine c. The disease typically progresses over months to years but can occur quickly following cessation of thyroid replacement medication or surgical removal. Hypothyroidism occurs in about 1 in 4000 newborns and neonatal screening is performed in most industrialized countries. Hypothyroidism or underactive thyroid is a common thyroid disorder in which the thyroid gland does not produce enough hormones. Hypothyroidism may occur as a result of primary gland failure or insufficient thyroid gland stimulation by the hypo thalamus or pituitary gland. Symptoms can manifest in all organ systems and range in severity based on the degree of hormone deficiency. Thyroxine t 4 and triiodothyronine t 3 are produced from the thyroid gland. Primary hypothyroidism is caused by the intrinsic dysfunction of the thyroid gland, and this is the most common type. The definition of hypothyroidism is based on statistical reference ranges of the relevant biochemical parameters and is increasingly a matter of debate. Most patients with hyperthyroidism have an enlarged thyroid gland goiter, but characteristics of the enlargement vary. The thyroid is a butterflyshaped gland located in the front of the neck just above the trachea. In very early or mild hypothyroidism, the tsh level will increase above normal level before the t4 drops below normal. It can be primary related to destruction of thyroid tissue or defective hormone synthesis or secondary related to pituitary disease with decreased tsh secretion or hypothalamic dysfunction.
The thyroid is a small, butterflyshaped gland in the front of your neck. The thyroid gland produces t4 and t3 utilizing iodide obtained either from dietary sources or from the. Hyperthyroidism, excess production of thyroid hormone by the thyroid gland. Hypothyroidism, also called myxedema, a deficiency in hormone production by the thyroid gland. The thyroid gland secretes hormones that help regulate the bodys metabolism how. Common causes are autoimmune disease, such as hashimotos thyroiditis, surgical removal of the thyroid, and radiation treatment. It is estimated that 3% to 5% of the population has some form of hypothyroidism. Secondary hypothyroidism is caused by a deficiency of thyroid stimulating hormone from the pituitary gland or deficiency of thyrotropinreleasing hormone from the hypothalamus. This misconception is more than 80 years old with owen thompson and colleagues2 reporting a high incidence of hypertension in myxoedema. Congenital primary hypothyroidism is caused by lack of or abnormal development of the thyroid in. For information on thyroid patient support organizations, please visit the. Whether or not subclinical hypothyroidism should be treated remains controversial. Understand the presentation, diagnostic process, treatment, and prognosis of hashimoto thyroiditis. It is treated by replacing the amount of hormone that your own thyroid can no longer make, to bring your t4 and tsh levels back to normal levels.
It weighs approximately 15 to 20 grams in the adult human. Recent advances have been made in understanding the molecular nature of the antigens that are the target of the immune system in hashimotos thyroiditis. Thyroid hormones control the way the body uses energy, so they affect nearly every. Download a pdf of this fact sheet here what is hypothyroidism. The causes and contributing factors to both subclinical and clinical or overt hypothyroidism are the same.
Hypothyroidism, a disease in which the thyroid gland does not make enough thyroid hormone, is the second most common endocrine disorder among women. The thyroid gland synthesizes the hormones thyroxine t4 and. In a normal, healthy person the thyroid is in a state of homeostasis with the rest of the body. Most thyroid checklists look only at the direct symptoms caused by hypothyroidism. Other causes are congenital deficiency of thyroid tissue or thyroid hormone. Identify sick euthyroid syndrome and other causes of abnormal thyroid function test results.
Primary hypothyroidism may be due to genetic defects of the thyroid or autoimmune or inflammatory systems. The american thyroid association ata is the leading organization devoted to thyroid biology and to the prevention and treatment of thyroid disease through. The most common cause of hypothyroidism in the united states is hashimotos thyroiditis. Thus, basic intracellular functions such as oxygen. Management consists of thyroid replacement therapy, along with pericardial drainage in case of tamponade. Hypothyroidism underactive thyroid is when the thyroid gland produces less thyroid hormone than it should. When the medicare program was established in 1965, it was. The occurrence varies with genetics with a high prevalence in caucasians, and the disease is more common in populations with a high iodine intake. The cause of the decrease in thyroid function may be due to many factors. Because the autoimmune process gradually reduces thyroid function, there is a phase of compensation when normal thyroid hormone. These septa also serve as conduits for blood vessels.
Hypothyroidism results from insufficient circulating thyroid hormone as a result of a variety of abnormalities. Pathophysiology of hashimotos thyroiditis and hypothyroidism. The provided hypothyroidism symptom checklist is extremely comprehensive. It is important to understand the function of the thyroid and the thyroid hormonesthyroidstimulating hormone tsh, triiodothyronine t3.
Pericardial diseases in patients with hypothyroidism heart. Autoimmune hashimotos thyroiditis, the most common endocrine disorder, is primarily a subclinical disease. The common causes of hypothyroidism are autoimmune destruction of the thyroid gland and previous thyroid surgery or radioiodine therapy. The complete hypothyroidism user guide for patients 2019. Clinical manifestations of hypothyroidism range from life threatening to no signs or. Free endocrinology books download ebooks online textbooks. Diagnosis the evaluation of patients with newonset hypothyroidism is quite limited. Thyroid nodules become autonomous and produce thyroid hormones independent of signals from either tsh or tshreceptor antibodies figure 1. The pathophysiology of hypothyroidism essay 608 words.
1496 563 462 181 783 708 69 1005 1521 512 1454 217 1073 301 1303 723 1252 1520 669 1101 238 9 908 1552 1262 479 229 721 319 65 632 1509 88 457 119 1321 636 493 1274 668 332 787 1400