Thyroid Diseases

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The thyroid gland is butterfly-shaped, small body organ that lies in the neck flat against the windpipe. Thyroid gland is very important organ that controls human body metabolism that is the valuation at which whole body uses energy. Thyroid produces thyroid hormones: thyroxine (T4) and triiodothyronine (T3) that migrate through blood to every organ of human body. These thyroid hormones say to body cells how fast to expense energy and produce proteins. The thyroid gland also produces calcitonin. Calcitonin is a hormone that regulates blood concentration of calcium by inhibiting the breakdown (reabsorption) of bone and extending calcium excretion from the kidneys.
The body has a well considered feedback system that controls T4 and T3 blood concentrations. When blood levels are low the hypothalamus releases thyrotopin-releasing hormone which as result causes the pituitary gland to release thyroid-stimulating hormone (TSH). Pituitary gland is a wee gland located below the brain and behind the sinus cavities. TSH incites the thyroid gland to make and secrete thyroid hormones. If the body has enough thyroid hormone in the blood the amount of TSH lowers to maintain constant levels of T4 and T3 thyroid hormones.
Main part of the T4 is stored bound to a protein called thyroglobulin inside the thyroid. If it is necessary the thyroid gland produces more T4 and releases some of what is stored. In the blood most T4 is bound to a protein called thyroxine-binding globulin (TBG) and is comparatively inactive. T4 is converted to T3 by the liver and in many other tissues. T3 controls the body functions rate.

Thyroid diseases are health conditions that affect thyroid hormones levels being produced. If it produces not enough amounts of thyroid hormones then it leads to hypothyroidism and a slowing of body functions. The symptoms of hypothyroidism include: dry skin, weight gain, cold intolerance, puffy skin, constipation, hair loss, fatigue, and menstrual irregularity in females. Heavy form of hypothyroidism is myxedema that can be cause of heart failure, seizures, and coma. Hypothyroidism in infants may stop growth and stunt sexual development. It may lead to mental retardation in children. For this cause, hypothyroidism testing is ordered as part of neonatal blood screening programs because early diagnosis and treatment can reduce long-term health problem.
When a thyroid disease produces excessive thyroid hormone level this leads to hyperthyroidism and the acceleration of body functions. The hyperthyroidism symptoms include: anxiety, increased heart rate, difficulty sleeping, weight loss, hands tremors, weakness, and diarrhea. Other sighs of hyperthyroidism: puffiness around the eyes, bulging of the eyes, irritation, and, dryness. Patients can feel visual disturbances and light sensitivity. The patient can appear to be staring since the eyes may not move as usual.

Common Thyroid Diseases
About 20 million Americans have some form of thyroid disease. These are the most common:

Graves' Disease – This is the most common cause of hyperthyroidism. It is a chronic disorder in which the affected person's immune system produces antibodies that attack the thyroid, causing inflammation, damage, and the production of excessive amounts of thyroid hormone.
Hashimoto's Thyroiditis – This is the most common cause of hypothyroidism in the United States. Like Graves' disease, it is a chronic autoimmune condition related to the production of antibodies that target the thyroid and cause inflammation and damage. With Hashimoto's thyroiditis, however, the body makes decreased amounts of thyroid hormone.

Thyroid Cancer—Thyroid cancer is fairly uncommon, with only about 1500 deaths and 33,550 new cases diagnosed in 2007 in the U.S. There are four main types of thyroid cancers: papillary, follicular, anaplastic, and medullary cancer. About 60-70% of thyroid cancer cases are papillary. This type affects more women than men and is more common in younger people. About 15% of thyroid cancers are follicular, a more aggressive type of cancer that tends to occur in older women. Anaplastic cancer, also found in older women, accounts for about 5% of thyroid cancers and tends to be both aggressive and difficult to treat. Medullary thyroid cancer (MTC) produces calcitonin and may be found alone or linked with other endocrine cancers in a syndrome called multiple endocrine neoplasia syndrome. MTC can also be difficult to treat if it spreads beyond the thyroid.

Thyroid Nodules—A thyroid nodule is a small lump on the thyroid gland that may be solid or a fluid-filled cyst. As many as 4% of women and 1% of men will have one or more thyroid nodules; however, the overwhelming majority of these nodules are harmless. Occasionally, thyroid nodules can be cancerous and need to be treated.

Thyroiditis—Thyroiditis is an inflammation of the thyroid gland. It may be associated with either hypo- or hyperthyroidism. It may be painful, feeling like a sore throat, or painless. Thyroiditis may be due to autoimmune activity, an infection, exposure to a chemical that is toxic to the thyroid, or an unkown cause. Depending on the cause, it can be acute but transient or chronic.

Goiters—A thyroid goiter is a visible enlargement of the thyroid gland. In the past, this condition was relatively common and was due to a lack of iodine in the diet. Iodine is a necessary component of thyroid hormone production. In the United States, where iodine is now routinely added to table salt (iodized) and used to clean milking cows' udders, the incidence of dietary-related goiters has declined significantly. In other parts of the world, however, iodine-related goiters are still common and represent the most common cause of hypothyroidism in some countries. Any of the diseases listed above can also cause goiters. Goiters may compress vital structures of the neck, including the trachea and esophagus. This compression can make it difficult to breathe and swallow.

Tests
Laboratory Tests
The first test your doctor will usually order to detect thyroid dysfunction is a TSH test. If your TSH level is abnormal, the doctor will usually order a total T4 or free T4 test to confirm the diagnosis. A total T3 or free T3 test may be ordered as well.
·TSH – to test for hypothyroidism, hyperthyroidism, screen newborns for hypothyroidism, and monitor thyroid replacement therapy  
·T4 or free T4 – to test for hypothyroidism and hyperthyroidism and to screen newborns for hypothyroidism  
·T3 or free T3 – to test for hyperthyroidism  
Additional tests that may be performed include:
·Thyroid antibodies - to help differentiate different types of thyroiditis and identify autoimmune thyroid conditions  
·Calcitonin - to help detect the presence of excessive calcitonin production  
Screening
Screening for thyroid disease is controversial, and there is no consensus in the medical community as to who would benefit from scrrening and at what age to begin. In 2004, the U.S. Preventive Services Task Force found insufficient evidence to recommend for or against routine screening for thyroid disease in adults. However, the American Thyroid Association currently recommends that everyone over 35 years of age be screened with a TSH test every 5 years, and the American Association of Clinical Endocrinologists recommends that all women be tested for hypothyroidism by 50 years of age (sooner if they have a family history of thyroid disease) as well as those who are or planning to become pregnant in order to detect thyroid problems.
Non-Laboratory Tests
·Thyroid Scans – a test that uses radioactive iodine or technetium to look for thyroid gland abnormalities and to evaluate thyroid function in different areas of the thyroid  
·Ultrasound – an imaging scan that allows doctors to determine whether a nodule is solid or fluid filled and can help measure the size of the thyroid gland  
·Biopsies – often a fine-needle biopsy, a procedure that involves inserting a needle into the thyroid and removing a small amount of tissue and/or fluid from a nodule or other area that the doctor wants to examine; an ultrasound is used to guide the needle into the correct position  

Treatment
Treatment for thyroid disease depends on the cause and the levels of hormone production. Therapy for disorders that cause hyperthyroidism may involve radioactive iodine (to destroy part or all of the thyroid), anti-thyroid drugs, or surgery to remove the thyroid. Sometimes all three of these treatments may be used. If the thyroid is destroyed or removed, the patient will become hypothyroid and will need to take synthetic thyroid hormones.
Treatment for thyroid cancers depends on the type of cancer and how far it has spread. Thyroid cancer often requires removal of all or part of the thyroid and may involve radioactive iodine treatment and treatment with thyroid hormones. While papillary cancer is usually easily treated and most cases are cured, the others can be a challenge. In some cases, radiation and chemotherapy are used before and after surgical removal of the thyroid.
Treatment for all types and causes of hypothyroidism is usually straightforward and involves thyroid hormone replacement therapy.


 
 
 
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All information on this page is intended for your general knowledge only and does not provide medical advice, diagnosis or treatment.