Thyroid Gland
Thyroid gland is an endocrine organ located in the front part of the neck, in front and both sides of the windpipe (trachea) and just in front of the voice box. It is butterfly shaped organ consisting of right and left lobes that are connected in the middle by isthmus.
Thyroid gland produces thyroid hormones which have an effect on heart rate, breathing, weight, muscle strength, central and peripheral nervous system, body temperature, menstrual cycle and others.
Thyroid gland produces 2 hormones, triiodothyronine (T3) and thyroxine (T4). Iodine in the diet is needed to produce these hormones. It is important that T3 and T4 levels are within normal range, too little and too much is not good for our health and causes many problems. Two glands in the brain, the hypothalamus and the pituitary gland, are also involved in maintaining normal balance of thyroid hormones.
The hypothalamus produces TSH Releasing Hormone (TRH) that signals to pituitary to tell the thyroid gland to produce more or less of T3/T4 by either increasing or decreasing the release of thyroid stimulating hormone (TSH). When T3 or T4 levels are low in the blood, the pituitary gland releases more TSH which will in turn increase the lecelv of thyroid hormones. If T3/T4 levels are high, pituitary produces less TSH which will decrease the levels of thyroid hormones.
T3 and T4 influence almost all cells in the body by influencing their metabolism, protein production and development.
Thyroid gland produces thyroid hormones which have an effect on heart rate, breathing, weight, muscle strength, central and peripheral nervous system, body temperature, menstrual cycle and others.
Thyroid gland produces 2 hormones, triiodothyronine (T3) and thyroxine (T4). Iodine in the diet is needed to produce these hormones. It is important that T3 and T4 levels are within normal range, too little and too much is not good for our health and causes many problems. Two glands in the brain, the hypothalamus and the pituitary gland, are also involved in maintaining normal balance of thyroid hormones.
The hypothalamus produces TSH Releasing Hormone (TRH) that signals to pituitary to tell the thyroid gland to produce more or less of T3/T4 by either increasing or decreasing the release of thyroid stimulating hormone (TSH). When T3 or T4 levels are low in the blood, the pituitary gland releases more TSH which will in turn increase the lecelv of thyroid hormones. If T3/T4 levels are high, pituitary produces less TSH which will decrease the levels of thyroid hormones.
T3 and T4 influence almost all cells in the body by influencing their metabolism, protein production and development.
Thyroid investigations
Blood Tests
TSH – best single blood test. Measures levels of thyroid stimulating hormone and should be normal. Measures thyroid function.
T4 and T3 – should be only measured if TSH is abnormal. Measures level of thyroid hormones (T4 and T3) in the blood.
Thyroglobulin – mostly performed as part of thyroid cancer follow-up. Not useful as screening test
Your endocrinologist may order some other thyroid tests, but these are otherwise not routinely performed.
Ultrasound
Ultrasound is the best investigation for looking at thyroid, especially in the context of nodules. Recently The American College of Radiology and The American Thyroid Association have developed a set of standard criteria (TI- RADS) for reporting of the thyroid nodules (TR1-TR5) to provide recommendations of management of these thyroid nodules. Depending on the TR classification, some of these nodules do not require any further investigation or follow-up. Some may only require follow-up with ultrasound and some may require biopsy.
Ultrasound guided Fine Needle Aspirate (FNA)
Ultrasound guided FNA is performed if ultrasound scan has shown thyroid nodules and one or more of these shows some suspicious features as per TI RADS criteria. The FNA is always performed using the ultrasound so that the correct nodule and area within the nodule is targeted on the biopsy. Blind (without ultrasound) biopsy should not be performed.
Nuclear Medicine thyroid scan
This thyroid scan uses radioactive tracer (Technetium 99mTc or radioiodine 123I) to measure how much of the tracer has been absorbed by thyroid gland. It is usually performed if patient has hyperthyroidism (overactive thyroid) to diagnose the cause of this. The uptake of the tracer may be uniform throughout the thyroid gland (Grave’s disease) or within one or more thyroid nodules.
Radioiodine treatment of hyperthyroidism or thyroid cancer uses different radioiodine tracer, it uses radioiodine 131I.
CT scan
This scan is not frequently used for investigating at the thyroid gland. It is usually used if you have very large thyroid to see how much of the thyroid is behind the breast bone (retrosternal) and if it is narrowing your windpipe.
In patients with thyroid cancer it may be used to assess whether the cancer is invading into the surrounding organs. This test is not commonly performed in these situations, as these cancers do not commonly involve surrounding structures.
TSH – best single blood test. Measures levels of thyroid stimulating hormone and should be normal. Measures thyroid function.
T4 and T3 – should be only measured if TSH is abnormal. Measures level of thyroid hormones (T4 and T3) in the blood.
Thyroglobulin – mostly performed as part of thyroid cancer follow-up. Not useful as screening test
Your endocrinologist may order some other thyroid tests, but these are otherwise not routinely performed.
Ultrasound
Ultrasound is the best investigation for looking at thyroid, especially in the context of nodules. Recently The American College of Radiology and The American Thyroid Association have developed a set of standard criteria (TI- RADS) for reporting of the thyroid nodules (TR1-TR5) to provide recommendations of management of these thyroid nodules. Depending on the TR classification, some of these nodules do not require any further investigation or follow-up. Some may only require follow-up with ultrasound and some may require biopsy.
Ultrasound guided Fine Needle Aspirate (FNA)
Ultrasound guided FNA is performed if ultrasound scan has shown thyroid nodules and one or more of these shows some suspicious features as per TI RADS criteria. The FNA is always performed using the ultrasound so that the correct nodule and area within the nodule is targeted on the biopsy. Blind (without ultrasound) biopsy should not be performed.
Nuclear Medicine thyroid scan
This thyroid scan uses radioactive tracer (Technetium 99mTc or radioiodine 123I) to measure how much of the tracer has been absorbed by thyroid gland. It is usually performed if patient has hyperthyroidism (overactive thyroid) to diagnose the cause of this. The uptake of the tracer may be uniform throughout the thyroid gland (Grave’s disease) or within one or more thyroid nodules.
Radioiodine treatment of hyperthyroidism or thyroid cancer uses different radioiodine tracer, it uses radioiodine 131I.
CT scan
This scan is not frequently used for investigating at the thyroid gland. It is usually used if you have very large thyroid to see how much of the thyroid is behind the breast bone (retrosternal) and if it is narrowing your windpipe.
In patients with thyroid cancer it may be used to assess whether the cancer is invading into the surrounding organs. This test is not commonly performed in these situations, as these cancers do not commonly involve surrounding structures.
BENIGN THYROID DISORDERS
1. Thyroid Nodules
Thyroid nodules are very common, they may be present in up to 70% of people. Majority of them are benign. Any new thyroid nodule or a thyroid nodule that has recently changed should be investigated to exclude cancer. Any history of exposure to high levels of radiation or family history of thyroid cancer are very important.
The most important investigation is ultrasound of the thyroid.
Recently The American College of Radiology and The American Thyroid Association have developed a set of standard criteria for reporting of the thyroid nodules TR1-TR5 to provide recommendations of management of these thyroid nodules. Depending on the TR classification, some of these nodules do not require any further investigation or follow-up. Some may only require follow-up with ultrasound and some may require biopsy.
Cysts are fluid collections within thyroid gland. Most of the time you may not even know that they are there. Sometimes they become large and they need to be aspirated with a needle and they may completely disappear. At times they will recur and very rarely thyroid surgery (thyroid lobectomy) will be performed.
Colloid Nodules are made up of thyroid tissue that have become large. Sometimes they are solitary, but more commonly there are many of these nodules present. At times fine needle aspiration (FNA) is required to exclude cancer. At times these may become very large and cause pressure symptoms or cosmetic deformity. If thyroid nodules are symptomatic, they may need removal of part or whole thyroid gland.
Thyroid adenomas are benign tumours caused by abnormal growth of thyroid cells. They do not metastasise (spread) or invade other tissues. The biggest problem is that these nodules are extremely difficult to be differentiated from thyroid cancer on FNA. Thyroid surgery is often recommended for diagnosis and usually consists of thyroid lobectomy.
Thyroid Goitre is a term used for enlarged thyroid. This enlargement is commonly caused by presence of nodule or nodules. At times it is also caused by Grave’s disease.
2. Hyperactive Thyroid (Hyperthyroidism or thyrotoxicosis)
Hyperthyroidism is caused by excess thyroid hormone. The symptoms may be: decrease or increase in appetite and weight, difficulty sleeping, fatigue, frequent bowel motions, heart racing, heat intolerance and sweating, irritability, change in periods, muscle weakness, tremor, dizziness, thinning of hair, itching etc. Hyperthyroidism is diagnosed by performing a blood test and measuring thyroid hormones and TSH. If thyrotoxicosis is not treated it may lead to problems with heart and heart failure, problems with fertility or osteoporosis.
The causes of hyperthyroidism may be due to excess iodine ingestion or thyroid hormone ingestion, inflammation of the thyroid (thyroiditis), solitary toxic nodule, multiple toxic nodules (thyrotoxic goiter) or due to Grave’s disease. These are best managed to endocrinologists, rated then endocrine or thyroid surgeon.
Treatment of hyperthyroidism usually consist of medical control of thyrotoxicosis with medications such as Carbimazole or Propothyouracil. If the treatment of thyrotoxicosis is unlikely to resolve with medications or medications are not tolerated, then the endocrinologist may recommend either radioactive iodine or surgery as treatment options.
Radioactive iodine is taken as a tablet and its absorption is concentrated in the thyroid. This usually requires admission to hospital for few days. The radiation causes injury and death of thyroid tissue. The effect is not immediate and it may take around 3 months for this to occur. The radioactive iodine is excreted in the urine, faeces and sweat over 1-2 weeks and during this time contact restrictions may be imposed to minimize effect of radiation to other people especially children and pregnant women).
Thyroid surgery may consist of hemithyroidectomy or total thyroidectomy. Hemithyroidectomy is removal of a lobe or ½ of thyroid gland. Total thyroidectomy is removal of whole thyroid gland. Hemithyroidectomy is usually performed in patients who have solitary nodule causing thyrotoxicosis. Total thyroidectomy is usually performed for Thyroitoxic multinodular goiter or for Grave’s disease.
3. Underactive Thyroid (Hypothyroidism)
Hypothyroidism is caused by lack of thyroid hormone. It is usually caused by failure of thyroid to produce enough thyroid hormone or can be a consequence of having thyroid surgery. Other causes are lack of iodine in the diet or Hashimoto’s thyroiditis.
The symptoms may be: poor ability to tolerate cold, tiredness, constipation, depression, weight gain. Hypothyroidism is diagnosed by performing a blood test and measuring thyroid hormones and TSH. If hypothyroidism is not treated it may lead to myxedema, a condition that causes swelling of tissues. This may lead to mental deterioration, psychosis, coma, hypothermia, low heart rated, heart failure and shortness of breath.
Treatment consists of taking thyroid replacement medications, usually in the form of thyroxine. Treatment never consists of surgery.
Thyroid nodules are very common, they may be present in up to 70% of people. Majority of them are benign. Any new thyroid nodule or a thyroid nodule that has recently changed should be investigated to exclude cancer. Any history of exposure to high levels of radiation or family history of thyroid cancer are very important.
The most important investigation is ultrasound of the thyroid.
Recently The American College of Radiology and The American Thyroid Association have developed a set of standard criteria for reporting of the thyroid nodules TR1-TR5 to provide recommendations of management of these thyroid nodules. Depending on the TR classification, some of these nodules do not require any further investigation or follow-up. Some may only require follow-up with ultrasound and some may require biopsy.
Cysts are fluid collections within thyroid gland. Most of the time you may not even know that they are there. Sometimes they become large and they need to be aspirated with a needle and they may completely disappear. At times they will recur and very rarely thyroid surgery (thyroid lobectomy) will be performed.
Colloid Nodules are made up of thyroid tissue that have become large. Sometimes they are solitary, but more commonly there are many of these nodules present. At times fine needle aspiration (FNA) is required to exclude cancer. At times these may become very large and cause pressure symptoms or cosmetic deformity. If thyroid nodules are symptomatic, they may need removal of part or whole thyroid gland.
Thyroid adenomas are benign tumours caused by abnormal growth of thyroid cells. They do not metastasise (spread) or invade other tissues. The biggest problem is that these nodules are extremely difficult to be differentiated from thyroid cancer on FNA. Thyroid surgery is often recommended for diagnosis and usually consists of thyroid lobectomy.
Thyroid Goitre is a term used for enlarged thyroid. This enlargement is commonly caused by presence of nodule or nodules. At times it is also caused by Grave’s disease.
2. Hyperactive Thyroid (Hyperthyroidism or thyrotoxicosis)
Hyperthyroidism is caused by excess thyroid hormone. The symptoms may be: decrease or increase in appetite and weight, difficulty sleeping, fatigue, frequent bowel motions, heart racing, heat intolerance and sweating, irritability, change in periods, muscle weakness, tremor, dizziness, thinning of hair, itching etc. Hyperthyroidism is diagnosed by performing a blood test and measuring thyroid hormones and TSH. If thyrotoxicosis is not treated it may lead to problems with heart and heart failure, problems with fertility or osteoporosis.
The causes of hyperthyroidism may be due to excess iodine ingestion or thyroid hormone ingestion, inflammation of the thyroid (thyroiditis), solitary toxic nodule, multiple toxic nodules (thyrotoxic goiter) or due to Grave’s disease. These are best managed to endocrinologists, rated then endocrine or thyroid surgeon.
Treatment of hyperthyroidism usually consist of medical control of thyrotoxicosis with medications such as Carbimazole or Propothyouracil. If the treatment of thyrotoxicosis is unlikely to resolve with medications or medications are not tolerated, then the endocrinologist may recommend either radioactive iodine or surgery as treatment options.
Radioactive iodine is taken as a tablet and its absorption is concentrated in the thyroid. This usually requires admission to hospital for few days. The radiation causes injury and death of thyroid tissue. The effect is not immediate and it may take around 3 months for this to occur. The radioactive iodine is excreted in the urine, faeces and sweat over 1-2 weeks and during this time contact restrictions may be imposed to minimize effect of radiation to other people especially children and pregnant women).
Thyroid surgery may consist of hemithyroidectomy or total thyroidectomy. Hemithyroidectomy is removal of a lobe or ½ of thyroid gland. Total thyroidectomy is removal of whole thyroid gland. Hemithyroidectomy is usually performed in patients who have solitary nodule causing thyrotoxicosis. Total thyroidectomy is usually performed for Thyroitoxic multinodular goiter or for Grave’s disease.
3. Underactive Thyroid (Hypothyroidism)
Hypothyroidism is caused by lack of thyroid hormone. It is usually caused by failure of thyroid to produce enough thyroid hormone or can be a consequence of having thyroid surgery. Other causes are lack of iodine in the diet or Hashimoto’s thyroiditis.
The symptoms may be: poor ability to tolerate cold, tiredness, constipation, depression, weight gain. Hypothyroidism is diagnosed by performing a blood test and measuring thyroid hormones and TSH. If hypothyroidism is not treated it may lead to myxedema, a condition that causes swelling of tissues. This may lead to mental deterioration, psychosis, coma, hypothermia, low heart rated, heart failure and shortness of breath.
Treatment consists of taking thyroid replacement medications, usually in the form of thyroxine. Treatment never consists of surgery.
THYROID SURGERY
THYROID SURGERY
Anser to question 4
POSSIBLE COMPLICATION FOLLOWING THYROID SURGERY
Answer to question 5
DO I NEED ANY ADDITIONAL MEDICATIONS FOLLOWING THYROID SURGERY
EXPECTED POSTOPERATIVE RECOVERY
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