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thyroid disorder
The thyroid gland is located in the neck and produces hormones that regulate metabolism. It contains two main hormones: T3 and T4. The thyroid is controlled by the hypothalamus and pituitary gland. Hypothyroidism is caused by an underactive thyroid and results in low hormone levels and symptoms like fatigue and weight gain. It is typically treated with levothyroxine hormone replacement therapy. Hyperthyroidism is caused by an overactive thyroid and results in high hormone levels and symptoms like weight loss and palpitations.
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thyroid disorder
- 1. Mardin mazhar Shangaismail Hawnaz hamasalh Hwda mhamad
- 2. Introduction of thyrod gland Second largest endocrine gland in body,Small butterfly shaped gland located at base of neck below the sternocleidomastoid muscles Thyroid is controlled by the hypothalmus and pituitary Weighs 18-60gms in adults,Histologically it is made up of follicular and parafollicular cells.
- 3. thyrod glandfolicular cell
- 4. Stimulates& maintains metabolic processes Produces thyroid hormones T3-triiodothyronine and T4-thyroxine These hormones regulate metabolism & affect the growth and function of other systems in the body Secretes calcitonin to lower serum calcium levels Parathyroid gland secretes PTH to raise serum calcium levels function
- 5. Function cont…….. Metabolic stimulants of: Neural and skeletal development Oxygen consumption at rest Stimulating bone turnover by increasing formation and resorption Promoting chronitropic and ionotropic effects Increasing number of catecholamine receptors in heart Increasing production of RBC Altering the metabolism of carbs, fats, and protein
- 6. Hormones: T3 &T4 T3 (Triiodothyronine) & T4 (Tetraiodothyronine Stored in Follicles (round sacs) in the thyroid filled with thyroglobulin, a thyroid protein. Dietary iodine enters follicles where they are stored as T3 and T4 T4 is converted to T3 by peripheral organs such as kidney, liver, and spleen T3 is 10x more active than T 4 Only 20% of total T3 is secreted by thyroid
- 7. Hormones: T4 T4-thyroxine contains 4 iodine atoms It is a slow-acting pre-hormone T4 takes 4 days to peak in blood Half-life 7 days Overall effects take 6 weeks T3 is the active and faster-acting hormone The immediate effects of T3 last 1-2 days Half-life 1.5 days
- 8. T3 and T4structure
- 9. Iodine Dietary Iodide is removed from the bloodstream by means of an active pump The pump can concentrate iodide in the follicular sacs at 350x greater than the blood concentration Oxidation of iodide by thyroid peroxidase converts iodide iodine Peripheral de-iodination of T4 to T3 is regulated by many factors including health, nutritional status, and other hormones
- 10. Hormones- TSH TSH TSH is a pituitary hormone Controlled by TRH-thyrotropin releasing hormone from hypothalamus Functions to stimulate thyroid hormone production May enlarge thyroid (goiter) when under producing Labs: High TSH indicates low thyroid hormone= hypo Low TSH indicates high thyroid hormone = hyper
- 11. Hormones-Calcitonin & Produced by thyroid to regulate serum calcium levels Calcitonin stimulates movement of calcium into bone Parathyroid hormone (PTH) opposite effect of calcitonin PTH
- 12. Negative Feedback System TRH TSH T3 & T4 Thyroid The disruption of any of these mechanisms can cause abnormal levels of T3 and T4 leading to thyroid disease
- 13. Hypothyroidism PrimaryHypothyroidism Disease of the thyroid gland Secondary Hypothyroidism Hypothalamic-pituitary diseases (reduced TSH)
- 14. Causes of Hypothyroidism PRIMARY Congenital Agenesis Ectopic thyroid remnants Defects of hormone synthesis Iodine deficiency Dyshormonogenesis Antithyroid drugs Other drugs (e.g. lithium, amiodarone, interferon)
- 15. Causes of Hypothyroidism Autoimmune Atrophic thyroiditis Hashimoto's thyroiditis Postpartum thyroiditis Infective Post-subacute thyroiditis
- 16. Iatrogenic Radioactive iodine therapy External neck irradiation post-surgery Infiltration amyloidosis, sarcoidosis, hemochromatosis, scleroderma Causes of Hypothyroidism
- 17. SECONDARY Hypopituitarism: tumors, pituitary surgery or irradiation, infiltrative disorders, Sheehan's syndrome, trauma, genetic forms of combined pituitary hormone deficiencies Isolated TSH deficiency or inactivity Hypothalamic disease: tumors, trauma, infiltrative disorders, idiopathic
- 18. Althoughanyone can develop hypothyroidism, you're at an increased risk if you: Are a woman older than age 60 Have an autoimmune disease Have a close relative, such as a parent or grandparent, with an autoimmune disease Have been treated with radioactive iodine or anti-thyroid medications Received radiation to your neck or upper chest Have had thyroid surgery (partial thyroidectomy) Have been pregnant or delivered a baby within the past six months Risk factor
- 19. signs and symptom Fatigue Increased sensitivity to cold Constipation Dry skin Unexplained weight gain Puffy face Hoarseness Muscle weakness Elevated blood cholesterol level Muscle aches, tenderness and stiffness Pain, stiffness or swelling in your joints Heavier than normal or irregular menstrual periods Thinning hair Slowed heart rate Depression Impaired memory
- 20. diagnosis Diagnosis of hypothyroidism is based on your symptoms and the results of blood tests that measure the level of TSH and sometimes the level of the thyroid hormone thyroxine. A low level of thyroxine and high level of TSH indicate an underactive thyroid. That's because your pituitary produces more TSH in an effort to stimulate your thyroid gland into producing more thyroid hormone.
- 21. Treatment Replacementtherapy with levothyroxine (thyroxine, i.e. T4) is given for life. In the young and fit, 100 - 150 μg daily is suitable. thyroid function tests after at least 2 months on a steady dose the aim is to restore T4 and TSH to well within the normal range An annual thyroid function test is recommended .
- 22. Excessiveamounts of the hormone can cause side effects, such as: Increased appetite Insomnia Heart palpitations Shakiness
- 23. Complication Goiter. Constant stimulation of your thyroid to release more hormones may cause the gland to become larger — a condition known as a goiter. Heart problems. Hypothyroidism may also be associated with an increased risk of heart disease, primarily because high levels of low-density lipoprotein (LDL) cholesterol — the "bad" cholesterol — can occur in people with an underactive thyroid. Mental health issues. Depression may occur early in hypothyroidism and may become more severe over time. Hypothyroidism can also cause slowed mental functioning.
- 24. Peripheralneuropathy. Long-term uncontrolled hypothyroidism can cause damage to your peripheral nerves — the nerves that carry information from your brain and spinal cord to the rest of your body, Myxedema. This rare, life-threatening condition is the result of long-term, undiagnosed hypothyroidism. Its signs and symptoms include intense cold intolerance and drowsiness followed by profound lethargy and unconsciousness. Infertility. Low levels of thyroid hormone can interfere with ovulation, which impairs fertility. Birth defects. Babies born to women with untreated thyroid disease may have a higher risk of birth defects than may babies born to healthy mothers. These children are also more prone to serious intellectual and developmental problems. Infants with untreated hypothyroidism present at birth are at risk of serious problems with both physical and mental development.
- 25. Hyperthyrodism Hyperthyroidism - result of excessive thyroid function major etiologies of thyrotoxicosis are hyperthyroidism caused by Graves' disease, toxic MNG, and toxic adenomas
- 26. Causes of hyperthyroidism Common Graves' disease (autoimmune) Toxic multinodular goitre Solitary toxic nodule/adenoma
- 27. Reasons for toomuch thyroxine (T-4) Graves' disease. Graves' disease, an autoimmune disorder in which antibodies produced by your immune system stimulate your thyroid to produce too much T-4, is the most common cause of hyperthyroidism. Hyperfunctioning thyroid nodules (toxic adenoma, toxic multinodular goiter, Plummer's disease). This form of hyperthyroidism occurs when one or more adenomas of your thyroid produce too much T-4. An adenoma is a part of the gland that has walled itself off from the rest of the gland, forming noncancerous (benign) lumps that may cause an enlargement of the thyroid. Not all adenomas produce excess T-4, and doctors aren't sure what causes some to begin producing too much hormone.
- 28. Cont…… Thyroiditis. Sometimes your thyroid gland can become inflamed for unknown reasons. The inflammation can cause excess thyroid hormone stored in the gland to leak into your bloodstream. One rare type of thyroiditis, known as subacute thyroiditis, causes pain in the thyroid gland. Other types are painless and may sometimes occur after pregnancy (postpartum thyroiditis).
- 29. Hyperthyrodism Clinical features: due to Hypermetabolic state Overactivity of sympathetic nervous system
- 30. Symptoms Weight loss Increased appetite Irritability Tremor Goiter Restlessness Stiffness Muscle weakness Breathlessness Palpitation Heat intolerance Excessive sweating Itching Thirst Vomiting Diarrhoea Oligomenorrhoea Loss of libido
- 31. Signs Tremor Irritability Psychosis Tachycardia or atrial fibrillation Warm peripheries Systolic hypertension Cardiac failure Lid lag Proximal myopathy Proximal muscle wasting Onycholysis Palmar erythema
- 32. diagnosis Medicalhistory and physical exam. During the exam your doctor may try to detect a slight tremor in your fingers when they're extended, overactive reflexes, eye changes and warm, moist skin. Your doctor will also examine your thyroid gland as you swallow. Blood tests. A diagnosis can be confirmed with blood tests that measure the levels of thyroxine and TSH in your blood. High levels of thyroxine and low or nonexistent amounts of TSH indicate an overactive thyroid.
- 33. If blood testsindicate hyperthyroidism, your doctor may recommend one of the following tests to help determine why your thyroid is overactive: Radioactive iodine uptake test. For this test, you take a small, oral dose of radioactive iodine (radioiodine). Over time, the iodine collects in your thyroid gland because your thyroid uses iodine to manufacture hormones. You'll be checked after two, six or 24 hours — and sometimes after all three time periods — to determine how much iodine your thyroid gland has absorbed. A high uptake of radioiodine indicates your thyroid gland is producing too much thyroxine. The most likely cause is either Graves' disease or hyperfunctioning nodules.
- 34. Thyroidscan. During this test, you'll have a radioactive isotope injected into the vein on the inside of your elbow or sometimes into a vein in your hand. You then lie on a table with your head stretched backward while a special camera produces an image of your thyroid on a computer screen. The time needed for the procedure may vary, depending on how long it takes the isotope to reach your thyroid gland. You may have some neck discomfort with this test, and you'll be exposed to a small amount of radiation.
- 35. Treatment Antithyroiddrugs: 1. Carbimazole. 2. Propylthiouracil. These drugs inhibit the formation of thyroid hormones common side effects - rash, urticaria, fever, and arthralgia Rare but major side effects include hepatitis; an SLE-like syndrome; and, most important, agranulocytosis
- 36. Treatment Radioactive iodine RAI accumulates in the thyroid and destroys the gland by local radiation. It takes several months to be fully effective. Surgery: subtotal thyroidectomy Only in patient who have previously been rendered euthyroid.
- 37. Goiter Goiter refers to an enlarged thyroid gland Biosynthetic defects, iodine deficiency, autoimmune disease, and nodular diseases can each lead to goiter diffuse nontoxic goiter - diffuse enlargement of the thyroid occurs in the absence of nodules and hyperthyroidism Worldwide, diffuse goiter is most commonly caused by iodine deficiency and is termed endemic goiter
- 38. Congenital Thyroid Diseases Agenesis /Aplasia Hypoplasia Accessory or aberrant thyroid glands Thyroglossal duct cyst
- 39. Thyroglossal Duct Cyst A thyroglossal duct cyst is a neck mass or lump that develops from cells and tissues remaining after the formation of the thyroid gland during embryonic development. Children Failure of regression Neck, medial Squamous or columnar lining often appears after an upper respiratory infection when it enlarges and becomes painful. Complications: inflammation, sinus tracts
- 40. Case with hypothyrodism History: A 50 year old housewife complains of progressive weight gain of 20 pounds in 1 year, fatigue, postural dizziness, loss of memory, slow speech, deepening of her voice, dry skin, constipation, and cold intolerance. Physical examination: Vital signs include a temperature 96.8oF, pulse 58/minute and regular, BP 110/60. She is moderately obese and speaks slowly and has a puffy face, with pale, cool, dry, and thick skin. The thyroid gland is not palpable. The deep tendon reflex time is delayed. Laboratory studies: CBC and differential WBC are normal. The serum T4 concentration is 3.8 ug/dl (N=4.5-12.5), the serum TSH is 1 uU/ml (N=0.2-3.5), and the serum cholesterol is 255 mg/dl (N<200)
- 41. History:A 35 year old nurse complained of nervousness, mood swings, weakness, and palpitations with exertion for the past 6 months. Recently, she noticed excessive sweating and wanted to sleep with fewer blankets than her husband. She used oral contraceptives and her menstrual periods were regular. Physical examination: Pulse was 92/minute and BP was 130/60. She appeared anxious, with a smooth, warm, and moist skin, a fine tremor, a bounding cardiac apical impulse, and she couldn't rise from a deep knee bend without aid. Her thyroid was diffusely enlarged, soft, mobile, without nodularity and there was no lymphadenopathy. Her eyes were not prominent (proptotic) and she had no focal skin thickening. Laboratory studies: Serum T4=15.6 ug/dl and serum T3=210 ng/dl. Case with hyperthyrodism
- 42.