Hyperthyroidism is a condition that occurs due to overproduction of thyroid hormone by the thyroid gland. Tirotoxicosis is a condition that occurs due to excessive thyroid hormone from any cause and therefore includes hyperthyroidism. Some, however, use the term interchangeably. Signs and symptoms vary between people and may include irritability, muscle weakness, sleep problems, rapid heartbeat, heat intolerance, diarrhea, thyroid enlargement, and weight loss. Symptoms are usually less on the old and during pregnancy. Unusual complications are thyroid storms where an event such as an infection results in worsening symptoms such as confusion and high temperature and often leads to death. The reverse is hypothyroidism, when the thyroid gland does not produce enough thyroid hormone.
Graves' disease is the cause of about 50% to 80% of cases of hyperthyroidism in the United States. Other causes include multinodular goiter, toxic adenoma, thyroid inflammation, overeating of iodine, and too much synthetic thyroid hormone. Less common cause is pituitary adenoma. Diagnosis can be suspected based on signs and symptoms and then confirmed by blood tests. Usually blood tests show low thyroid stimulation hormone (TSH) and elevate T 3 or T 4 . The uptake of radioiodin by the thyroid, thyroid scan, and TSI antibodies can help determine the cause.
Treatment depends in part on the cause and severity of the disease. There are three main treatment options: radioiodine therapy, medication, and thyroid surgery. Radioiodine therapy involves taking iodine-131â € through the mouth which then concentrates and destroys the thyroid for several weeks for months. The resulting hypothyroidism is treated with synthetic thyroid hormones. Drugs such as beta blockers can control the symptoms, and anti-thyroid medications such as methimazole can temporarily help temporarily while other treatments have an effect. Surgery to remove the thyroid is another option. It can be used on those with a very large thyroid or when the cancer becomes a concern. In the United States hyperthyroidism affects about 1.2% of the population. Occurs between two and ten times more often in women. The onset is generally between 20 and 50 years. Overall the disease is more common in those over the age of 60 years.
Video Hyperthyroidism
Signs and symptoms
Hyperthyroidism can be asymptomatic or present with significant symptoms. Some of the symptoms of hyperthyroidism include nervousness, irritability, increased perspiration, heart rate, hand tremor, anxiety, sleeplessness, skin thinning, brittle hair and muscle weakness - especially in the upper arm and thigh. More frequent bowel movements can occur, and diarrhea is common. Weight loss, sometimes significant, can occur despite a good appetite (although 10% of people with hyperactivity experience increased thyroid weight), vomiting may occur, and, for women, menstrual flow may be relieved and menstrual periods may occur less frequently, or with longer cycles than usual.
Thyroid hormones are essential for normal cell function. Excessively, both stimulate metabolism and exacerbate the effects of the sympathetic nervous system, leading to "accelerate" of various body systems and symptoms resembling epinephrine overdose (adrenaline). These include rapid heartbeat and palpitations, nervous system tremors such as hand and anxiety symptoms, hypermotility digestive system, undesirable weight loss, and (in "lipid panel" serum blood tests) lower serum cholesterol and sometimes overwhelming low.
The main clinical signs include weight loss (often accompanied by increased appetite), anxiety, heat intolerance, hair loss (especially the outer third of the eyebrow), muscle aches, weakness, fatigue, hyperactivity, irritability, high blood sugar, excessive urination, excessive thirst, delirium, tremor, pretibial myxedema (in Graves' disease), emotional lability, and sweating. Panic attacks, inability to concentrate, and memory problems can also occur. Psychosis and paranoia, common during thyroid storms, are rare with milder hyperthyroidism. Many people will experience full symptom remission 1 to 2 months after the eutyroid state is obtained, with anxiety reduction, fatigue, irritability, and depression. Some individuals may experience increased anxiety or persistence of affective and cognitive symptoms for months to 10 years after the euthyroid state is established. In addition, those with hyperthyroidism may present with various physical symptoms such as palpitations and abnormal heart rhythms (known as atrial fibrillation), shortness of breath (dyspnea), loss of libido, amenorrhea, nausea, vomiting, diarrhea, gynecomastia and feminization. Untreated long-term hyperthyroidism can cause osteoporosis. These classic symptoms may not often occur in the elderly.
Neurologic manifestations may include tremor, chorea, myopathy, and in some susceptible individuals (especially in Asian descent) periodic paralysis. The relationship between thyroid disease and myasthenia gravis has been recognized. Thyroid disease, in this condition, is autoimmune and about 5% of patients with myasthenia gravis also develop hyperthyroidism. Myasthenia gravis rarely improves after thyroid treatment and the relationship between the two entities is not well understood.
In Graves' disease, ophthalmopathy can cause the eyes to appear enlarged because the eye muscles swell and push the eye forward. Sometimes, one or both eyes can stand out. Some have swelling in front of the neck of the enlarged thyroid gland (goiter).
Minor ocular signs, which may be present in all types of hyperthyroidism, are eyelid retraction ("gaze"), extraocular muscle weakness, and lag delay. On hyperthyroid staring (Dalrymple's sign) the eyelid is pulled upwards more than normal (the normal position is in the superior corneoscleral limbus, where the "white" eye starts at the upper border of the iris). Extraocular muscle weakness may present with double vision. In the eyelid (von Graefe's sign), when the patient traces the object down with their eyes, the eyelid fails to follow the slices that move downward, and the same kind of the same upper exposure as seen by the lid retraction takes place, temporarily. These signs disappear with the treatment of hyperthyroidism.
None of the ocular signs should be confused with exophthalmos, which occurs specifically and uniquely in hyperthyroidism caused by Graves 'disease (note that not all exophthalmos is caused by Graves' disease, but when present with hyperthyroidism is diagnostic Disease grave). This advanced protrusion of the eyes is caused by immune-mediated inflammation in the retro-orbital (slim eye) of fat. Exophthalmos, at present, may aggravate hypertrophy and soar hyperthyroidism.
Thyroid storm
Thyroid storm is a form of severe thyrotoxicosis characterized by rapid and often irregular heartbeat, high temperature, vomiting, diarrhea, and mental agitation. The symptoms may be unusual in young, old, or pregnant people. This is a medical emergency and requires hospitalization to control symptoms quickly. Even with treatment, death occurs in 20% to 50%.
Hypothyroidism
Hyperthyroidism due to certain types of thyroiditis can cause hypothyroidism (thyroid hormone deficiency), because the thyroid gland is damaged. Also, the treatment of Graves' radioiodine disease often ends up leading to hypothyroidism. Such hypothyroidism can be treated with routine thyroid hormone testing and oral thyroid hormone supplementation.
Maps Hyperthyroidism
Cause
There are several causes of hyperthyroidism. Most often, the entire gland produces too much thyroid hormone. Less commonly, single nodules are responsible for the excess secretion of hormones, called "hot" nodules. Thyroiditis can also cause hyperthyroidism. Functional thyroid tissue produces excess thyroid hormones occurring in a number of clinical conditions.
The main causes in humans are:
- Graves' Disease. Autoimmune diseases (typically, the most common etiologies with 50-80% worldwide, though this varies substantially with location-that is, 47% in Switzerland (Horst et al., 1987) to 90% in the United States (Hamburger et al. 1981)). Expected because of the various levels of iodine in the diet. This is eight times more common in women than men and often occurs in young women, about 20-40 years.
- The toxic thyroid adenoma (the most common etiology in Switzerland, 53%, is considered abnormal because of the low levels of dietary iodine in this country)
- The toxic multinodular itch
High levels of the thyroid hormone in the blood (called hyperthyroxinemia) can occur for a number of other reasons:
- Thyroid inflammation is called thyroiditis. There are several types of thyroiditis including Hashimoto's thyroiditis (Hypothyroidism immune-mediated), and subacute thyroiditis (de Quervain's). This may be initially linked to excess secretion of the thyroid hormone but usually develops into glandular dysfunction and, thus, hormone deficiency and hypothyroidism. Oral consumption of excess thyroid hormone tablets is possible (the use of thyroid hormones secretly), such as the rare occurrence of consumption of beef contaminated with thyroid tissue, and thus thyroid hormone (called "hyperthyroidism hamburger"). Pharmaceutical incorporation errors can also be the cause.
- Amiodarone, an antiarrhythmic drug, is structurally similar to thyroxine and may cause a lack of thyroid or overactivity.
- Postpartum thyroiditis (PPT) occurs in about 7% of women during the year after they give birth. PPT usually has several phases, the first is hyperthyroidism. This form of hyperthyroidism usually corrects itself in weeks or months without treatment.
- Struma ovarii is a rare form of monodermal teratoma that contains most of the thyroid tissue, leading to hyperthyroidism.
- Excessive consumption of iodine, especially from algae such as seaweed.
Thyrotoxicosis can also occur after taking too much of the thyroid hormone in supplement form, such as levothyroxine (a phenomenon known as exogenous thyrotoxicosis, alimentary thyrotoxicosis, or thyrotoxicosis of the occult fact).
Hypersecretion of thyroid stimulating hormone (TSH), which in turn is almost always caused by pituitary adenoma, accounts for less than 1 percent of cases of hyperthyroidism.
Diagnosis
Measuring the level of thyroid-stimulating hormone (TSH), produced by the pituitary gland (which in turn is also regulated by the hypothalamus TSH Releasing Hormone) in the blood is usually a preliminary test for hyperthyroidism presumptions. A low TSH level usually indicates that the pituitary gland is being inhibited or "instructed" by the brain to cut back on stimulating the thyroid gland, after feeling an increase in T 4 and/or T 3 in the blood. In rare circumstances, low TSH indicates a primary failure of the pituitary, or temporary inhibition of the pituitary due to another disease (euthyroid sick syndrome) and so checking T 4 and T 3 is still useful clinical.
Measuring specific antibodies, such as anti-TSH-receptor antibodies in Graves' disease, or anti-thyroid peroxidase in Hashimoto's thyroiditis - a common cause of hypothyroidism - may also contribute to the diagnosis.
The diagnosis of hyperthyroidism was confirmed by blood tests that showed a decrease in thyroid-stimulating hormone (TSH) and increased T 4 and T 3 . TSH is a hormone made by the pituitary gland in the brain that tells the thyroid gland how much hormone it produces. When there is too much thyroid hormone, TSH will become low. The radioactive iodine absorption test and thyroid scan together mark or allow radiologists and physicians to determine the cause of hyperthyroidism. The absorption test using radioactive iodine is injected or taken orally on an empty stomach to measure the amount of iodine absorbed by the thyroid gland. People with hyperthyroidism absorb more iodine than healthy people who include radioactive iodine that is easily measured. Thyroid scanning generating images is usually done in connection with an uptake test to allow visual examination of excessive functioning glands.
Thyroid scintigraphy is a useful test for characterizing (distinguishing causes) of hyperthyroidism, and this entity from thyroiditis. This test procedure usually involves two tests performed in connection with each other: iodine uptake test and imaging with gamma camera. The absorption test involves administering a dose of radioactive iodine (radioiodine), traditionally iodine-131 ( 131 I), and more recently iodine-123 ( 123 I). Iodine-123 can be the preferred radionuclide in some clinics because of the more favorable radiation dosimetry (ie less radiation doses for patients per given radioactive unit) and gamma photon energy that is easier to imaging with gamma cameras. For imaging scanning, I-123 is considered the ideal iodine isotope for imaging thyroid tissue and metastatic thyroid cancer.
General administration involves pills or liquids containing sodium iodide (NaI) taken orally, containing a small amount of iodine-131, as much as less than a grain of salt. 2 hours of fasting without food before and for 1 hour after swallowing pills is required. This low dose of radioiodin is usually tolerated by individuals who are allergic to iodine (such as those who can not tolerate iodine-containing contrast media in larger doses as used in CT scans, IVPs, and similar imaging diagnostic procedures). The excess radioiodin that is not absorbed into the thyroid gland is removed by the body in the urine. Some patients may experience slight allergic reactions to diagnostic radioiodine and may be given antihistamines.
The patient returns 24 hours later to have an "absorbed" radioiodine level (absorbed by the thyroid gland) as measured by a device with a metal rod placed on the neck, which measures the radioactivity that radiates from the thyroid. This test takes about 4 minutes while accumulated% is accumulated (calculated) by machine software. Scanning is also done, where the image (usually the center, the left and right corners) is taken from the thyroid gland in contrast to the gamma camera; a radiologist will read and prepare a report that shows% uptake and comments after checking the image. Hyperthyroid patients usually "take" higher than normal levels of radioiodine. The normal range for RAI uptake is from 10-30%.
In addition to testing the TSH level, many doctors are testing T 3 , Free T 3 , T 4 , and/or T Free 4 for more detailed results. The typical adult limit for these hormones is: TSH (unit): 0.45 - 4.50 uIU/mL; T 4 Free/Direct (nanogram): 0.82 - 1.77 ng/dl; and T 3 (nanogram): 71 - 180 ng/dl. People with hyperthyroidism can easily indicate the level of many of these upper limits for T 4 and/or T 3 . See full table of normal range limits for thyroid function on thyroid gland articles.
Pada hipertiroidisme CK-MB (Creatine kinase) biasanya meningkat.
Subklinis
In clear primary hyperthyroidism, low TSH levels and levels of T 4 and T 3 are high. Subclinical hyperthyroidism is a milder form of hyperthyroidism characterized by low or undetectable serum TSH levels, but with normal serum-free thyroxine levels. Although the evidence for doing so is not definitive, treatment of parents with subclinical hyperthyroidism may reduce the incidence of atrial fibrillation. There is also an increased risk of fracture (by 42%) in people with subclinical hyperthyroidism; there is insufficient evidence to say whether treatment with antithyroid drugs will reduce that risk.
Screening
In those without symptoms who are not pregnant, there is little evidence for or against screening.
Treatment
Antithyroid drugs
Thyrostatics are drugs that inhibit thyroid hormone production, such as carbimazole (used in the UK) and methimazole (used in the US, Germany and Russia), and propylthiouracil. Thyrostatics is believed to work by inhibiting thyroglobulin iodination by thyroperoxidase and, thus, the formation of tetraiodothyronine (T 4 ). Propylthiouracil also works outside the thyroid gland, preventing conversion (mostly inactive) T 4 to active form T 3 . Because thyroid tissue usually contains substantial thyroid hormone reserves, it can take weeks to become effective and frequent doses need to be titrated carefully for several months, with regular doctor visits and blood tests to monitor the results.
Very high doses are often needed at the beginning of treatment, but, if too high doses are used persistently, the patient may develop symptoms of hypothyroidism. Titration of this dose is difficult to do accurately, and sometimes the "block and replace" attitude is taken. In blocking and replacing treatments, thyrostatics are taken in sufficient quantities to completely block thyroid hormones, and patients are treated as if they have complete hypothyroidism.
Beta-blocker
Many of the common symptoms of hyperthyroidism such as palpitation, shaking, and anxiety are mediated by increased beta-adrenergic receptors on the cell surface. Beta blockers, commonly used to treat high blood pressure, are a class of drugs that offset this effect, reducing the rapid pulse associated with palpitations sensation, and decreased tremor and anxiety. Thus, a patient suffering from hyperthyroidism can often obtain temporary relief until hyperthyroidism can be characterized by the above mentioned Radioiodine test and more permanent treatment occurs. Note that these drugs do not treat hyperthyroidism or its long-term effects if left untreated, but, rather, they treat or simply reduce the symptoms of the condition.
Some of the minimal effects on thyroid hormone production but also come with Propranolol - which has two roles in the treatment of hyperthyroidism, is determined by different propranolol isomers. L-propranolol causes beta-blockade, thus treating symptoms associated with hyperthyroidism such as tremor, palpitations, anxiety, and heat intolerance. D-propranolol inhibits thioxine deiodinase, thereby inhibiting the conversion of T 4 to T 3 , giving some therapeutic effect even if minimal. Other beta-blockers are used to treat only the symptoms associated with hyperthyroidism. Propranolol in the UK, and metoprolol in the US, is most commonly used to supplement the treatment for hyperthyroid patients.
Diet
People with autoimmune hyperthyroidism should not eat foods high in iodine, such as edible seaweed and kelps.
From a public health perspective, the general introduction of iodized salt in the United States in 1924 resulted in lower disease, mumps, and improved the lives of children whose mothers did not eat enough iodine during pregnancy that would lower IQs from their children.
Surgery
Surgery (thyroidectomy to remove all thyroid or part of it) is not widely used because the most common form of hyperthyroidism is quite effectively treated by radioactive iodine methods, and because of the risk of also removing the parathyroid glands, and bypassing the recurrent laryngeal nerves, making swallowing difficult, and even only common staphylococcal infections as well as major surgery. Some people with Graves' can opt for surgical intervention. These include those who can not tolerate drugs for one reason or another, people allergic to iodine, or people who refuse radioiodine.
If a person has a toxic nodule treatment usually includes the removal or injection of nodules with alcohol.
Radioiodine
In the therapy of radioisotopes iodine-131 (radioiodine), which was first pioneered by Dr. Saul Hertz, radioactive iodine-131 is given orally (either by pill or liquid) at a time, to severely limit, or completely destroy the function of the hyperactive thyroid gland. This radioactive iodine isotope used for ablative treatment is stronger than radioiodine diagnostics (usually iodine-123 or very low amounts of iodine-131), which has a biological half-life of 8-13 hours. Iodine-131, which also emits beta particles that are much more destructive to tissues at short distances, has a half-life of about 8 days. Patients who do not respond adequately to the first dose are sometimes given additional radioiodine treatment, with larger doses. Iodine-131 in this treatment is taken by the active cells in the thyroid and destroys them, making the thyroid gland largely or completely inactive.
Because iodine is more easily taken (though not exclusively) by thyroid cells, and (more importantly) is picked up even more quickly by overactive thyroid cells, localized destruction, and no extensive side effects with this therapy. Radioiodine ablation has been used for more than 50 years, and the only main reason for not using it is pregnancy and breastfeeding (breast tissue also takes and concentrates iodine). Once the thyroid function is reduced, oral hormone therapy taken orally every day can easily provide the amount of thyroid hormone the body needs. There is extensive experience, over the years, the use of radioiodine in the treatment of thyroid overactivity and this experience did not show an increased risk of thyroid cancer after treatment. However, a study from 2007 has reported an increase in cancer incidence after the treatment of radioiodine for hyperthyroidism.
The main advantage of radioiodine treatment for hyperthyroidism is that it tends to have a much higher rate of success than drugs. Depending on the radioiodine dose selected, and the disease under treatment (Graves' versus toxic goitre, vs. hot nodules etc.), the success rate in achieving a definitive resolution of hyperthyroidism may vary from 75-100%. The main expected side effect of radioiodine in patients with Graves' disease is the development of lifelong hypothyroidism, which requires daily care with thyroid hormone. Occasionally, some patients may require more than one radioactive treatment, depending on the type of disease, thyroid size, and initial dose given.
Patients with Graves' disease who show moderate or severe ophthalmopathy Graves are warned against radioactive iodine-131 treatment, as it has been shown to aggravate existing thyroid eye disease. Patients with mild or absent ophthalmic symptoms may reduce their risk with prednisone for six weeks. The proposed mechanism for these side effects involves a common TSH receptor for both thyrocytes and retro-orbital tissues.
As a result of radioactive iodine treatment in the destruction of thyroid tissue, there is often a transient period of several days to weeks when symptoms of hyperthyroidism may actually worsen after radioactive iodine therapy. In general, this occurs as a result of thyroid hormones released into the blood after the destruction of radioactive iodine-mediated thyroid cells that contain thyroid hormones. In some patients, treatment with drugs such as beta blockers (propranolol, atenolol, etc.) may be useful during this time period.
Most patients experience no difficulty after the treatment of radioactive iodine, usually given as a small pill. Occasionally, neck pain or sore throat may become apparent after a few days, if moderate inflammation in the thyroid develops and produces discomfort in the neck or throat region. This is usually temporary, and is not associated with fever, etc.
Breastfeeding women should stop breastfeeding for at least a week, and may take longer, following radioactive iodine treatment, as small amounts of radioactive iodine can be found in breast milk even weeks after radioactive iodine treatment.
The general result after radioiodine is a swing from hyperthyroidism to easily treatable hypothyroidism, which occurs in 78% of those treated for Graves thyrotoxicosis and in 40% of those with toxic multinodular goiter or solitary toxic adenoma. Higher use of radioiodine doses reduces the incidence of treatment failure, with penalties for a higher response to treatment consisting mostly of a higher rate of ultimate hypothyroidism requiring lifelong hormone treatment.
There is an increased sensitivity to radioiodine therapy in the thyroid that appears on ultrasound scans as they are more uniform (hypoechogenic), due to large dense cells, with 81% subsequently becoming hypothyroid, compared to only 37% in those with more normal scores (normoechogenic ).
Thyroid storm
Thyroid storms present with symptoms of extreme hyperthyroidism. This is treated aggressively with resuscitation measures along with the above combinations of modalities including: intravenous beta blockers such as propranolol, followed by thioamides such as methimazole, iodinated radiocontrast agent or iodine solution if radiocontrast agents are not available, and an intravenous steroid such as hydrocortisone.
Epidemiology
In the United States hyperthyroidism affects about 1.2% of the population. About half of these cases have obvious symptoms while the other half do not. Occurs between two and ten times more often in women. This disease is more common in people over the age of 60 years.
Subclinical hyperthyroidism simply increases the risk of cognitive impairment and dementia.
History
Caleb Hillier Parry first made a connection between the goiter and the bulge of the eye in 1786, however, did not publish his discovery until 1825. In 1835, Irish physician Robert James Graves discovered the connection between the eyebrow and mumps, giving it a name for an autoimmune disease now known as Graves' Disease '.
Pregnancy
Recognizing and evaluating hyperthyroidism in pregnancy is a diagnostic challenge. Thyroid hormones are naturally elevated during pregnancy and hyperthyroidism should also be distinguished from gestational transient tirotoksikosis. However, high maternal FT4 levels during pregnancy have been associated with impaired brain development outcomes of heredity and this does not depend on hCG levels for example.
Other animals
Cat
Hyperthyroidism is one of the most common endocrine conditions that affects older pet housecats. Some veterinarians estimate that it occurs in 2% of cats above the age of 10 years. The disease has become more common in general since the first report of cat hyperthyroidism in the 1970s. One of the causes of hyperthyroidism in cats is the presence of benign tumors, but the reason these cats develop these tumors continues to be studied. However, a recent study published in Environmental Science & amp; Technology, a publication of the American Chemical Society, suggests that many cases of cat hyperthyroidism are associated with exposure to environmental contaminants called polybrominated diphenyl ethers (PBDEs), which are present in flame retardants in many household products, in particular, furniture and some electronics..
The study's underlying report was conducted jointly by researchers at the EPA's National Health and Environmental Impact Laboratory and the Indiana University. In the study, which involved 23 pet cats with cat hyperthyroidism, PBDE blood levels were three times higher than in younger and non-hyperthyroid cats. Under ideal circumstances, PBDE and related endocrine disorders that seriously damage health are not present in animal blood, including humans.
Some studies have shown that canned fish, liver and snacks prepared with cat food may increase the risk while fertilizers, herbicides, or plant pesticides have no effect. Another study shows cat feces can be a problem.
Mutations of thyroid stimulating hormone receptors that cause the constitutive activation of thyroid gland cells have been found recently. Many other factors may play a role in the pathogenesis of diseases such as goitrogens (isoflavones such as genistein, daidzein, and quercetin) as well as iodine and selenium from the diet of cats.
The most common symptoms are: rapid weight loss, tachycardia (rapid heartbeat), vomiting, diarrhea, increased consumption of fluids (polidipsia) and food, and increased urine production (polyuria). Other symptoms include hyperactivity, possible aggression, cardiac murmurs, gallop rhythms, unkempt appearance, and thick and thick claws. Approximately 70% of cats who suffer also have an enlarged thyroid gland (goiter).
The same three treatments used with humans are also an option in treating cat hyperthyroidism (surgery, radioiodin treatment, and anti-thyroid drugs). The drug used to help reduce hyperthyroidism is methimazole. Where drug therapy is used it should be given to cats for the rest of their lives but this may be the least expensive option, especially for very old cats. Anti-thyroid drugs for cats are available in pill form and topical gel, which is applied using a finger band to a skin that is not hairy on the cat's ear. Many cat owners find this gel as a good choice for cats who do not like to be given pills. Radioiodine care and surgery often cure hyperthyroidism but some veterinarians prefer radioiodine treatment rather than surgery because it carries no risk associated with anesthesia.
However, radioiodine treatment is not available in all areas for cats because it requires nuclear radiology expertise and facilities because cat urine, sweat, saliva and faeces are radioactive for several days after treatment that requires treatment and special facilities for inpatients usually for total of 3 weeks (first week in total isolation and next two weeks in close confinement). In the United States, guidelines for radiation levels vary from state to state; some countries such as Massachusetts allow hospitalization for as little as two days before the animals are sent home with care instructions. Surgery tends to be performed only when one of the thyroid gland is exposed (unilateral disease); However, after surgery, the remaining glands can become overactive. As in people, one of the most common complications of surgery is hypothyroidism.
Dog
Hyperthyroidism is much less common in dogs than in cats. Hyperthyroidism may be caused by a thyroid tumor. This may be a thyroid carcinoma. Approximately 90% of carcinomas are very aggressive; they attack the surrounding tissue and metastasize (spread), to other tissues, especially the lungs. It has a poor prognosis. Surgery to remove a carcinoma tumor is often very difficult, as the spread of the tumor to surrounding tissues, for example, to the arteries, esophagus, or throat. It is possible to reduce tumor size, thus eliminating symptoms and allowing time for other treatments to work. Approximately 10% of benign thyroid tumors; this often causes some symptoms.
In dogs treated for hypothyroidism (thyroid hormone deficiency), hyperthyroidism may occur as a result of an overdose of a thyroid hormone replacement drug, levothyroxine; in this case treatment involves a reduction in levothyroxine dose. Dogs that exhibit coprophagy, that is, who often eat dirt, and who live in households with dogs receiving levothyroxine treatment, may develop hyperthryoidism if they often eat feces from dogs receiving levothyroxine treatment.
Hyperthyroidism can occur if the dog eats a lot of thyroid gland tissue. This has happened to dogs fed commercial dogs.
See also
- High-impact heart failure
- The Jod-Basedow phenomenon
References
External links
- Manual article on hyperthyroidism
- Gina Spadafori (January 20, 1997). "Hyperthyroidism: A Common Disease in Older Cats". The Pet Connection . Veterinary Information Network . Retrieved January 28 2007 . >
- Brent, Gregory A. (Ed.), Thyroid Functional Testing , New York: Springer, Series: Endocrine Updates, Vol. 28, 1st Edition., 2010. ISBNÃ, 978-1-4419-1484-2
- Siraj, Elias S. (June 2008). "Update on Diagnosis and Treatment of Hyperthyroidism" (PDF) . Clinical Results Management Journal . 15 (6): 298-307 . Retrieved June 24 2009 .
Source of the article : Wikipedia
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