12 甲状腺功能亢进症与甲状腺功能减退症2

null Hyperthyroidism Hyperthyroidism 甲状腺功能亢进症NEW WORDSNEW WORDSThyroitoxicosis 甲状腺素中毒 Hyperthyroidism 甲亢 Palpitation 心悸 Sinus tachycardia 窦性心动过速 Atrial fibrillation 房颤 Proximal myopathy 近端肌病 Angina 心绞痛NEW WORDS (2)NEW WORDS (2)Diarrhoea 腹泻 Oligomenorrhoea 月经过少，月经稀发 Subfertility 低生育力 Eyelid retraction 眼睑挛缩 Lid lag 睑合滞后 Multinodular 多小结的 Adenoma 腺瘤 Thyroiditis 甲状腺炎 Amiodarone 胺碘酮 NEW WORDSNEW WORDSOrbital muscle 眼眶肌 Exophthalmos 突眼症 Symptomatic 有关症状的 Congenital 先天性的 Oral contraceptive pill 口服避孕药 Nephrotic syndrome 肾病综合征 Toxicosis 中毒症 Subtotal thyroidectomy 甲状腺次全切除术Thyrotoxicosis(甲状腺素中毒症)Thyrotoxicosis(甲状腺素中毒症) Thyrotoxicosis occurs when tissues are exposed to high levels of the thyroid hormones. Hyperthyroidism can occurHyperthyroidism can occur From the over- activity of the thyroid gland from ingestion of too much T4 rarely, from increased pituitary stimulation of the thyroid CLINICAL FEATURESCLINICAL FEATURES The clinical features of hyperthyroidism may be dramatic and include: weight loss despite normal appetite sweating and heat intolerance fatigue Palpitation(心悸) -- sinus tachycardia or atrial fibrillation agitation and tremor（易激怒，激动） generalized muscle weakness; proximal myopathy angina （心绞痛）and heart failure diarrhoea oligomenorrhoea and subfertility goitre eyelid retraction and lid lag. CAUSES CAUSES Hyperthyroidism can result from: Graves’ disease, diffuse （弥漫性的）toxic goitre toxic multinodular （多小结的）goitre solitary toxic adenoma thyroiditis exogenously administered iodine and iodine-containing drugs, e.g. amiodarone excessive T4 and T3 ingestion.Graves' disease (1)Graves' disease (1) Graves' disease is the most common cause of hyperthyroidism. It is an autoimmune disease in which antibodies to the TSH receptor on the surface of thyroid cells appear to mimic（vt.摹拟） the action of the pituitary hormone. The normal regulatory controls on T4 synthesis and secretion are lacking. Pituitary secretion of TSH is completely inhibited by the high concentrations of thyroid hormones in the blood. GRAVES’DISEASE(2) GRAVES’DISEASE(2) The eyelid retraction is commonlly seen in the patient with Graves’ disease (Fig. 3) nullGraves’disease (3) --the eyelid retractionGraves’disease (3) --the eyelid retractionIt is mostly due to the effects of high thyroid hormone concentration. But not all of the eye signs is caused this way. Rather, the thyroid and orbital muscle may have a common antigen which is recognized by the circulating autoantibodies. The inflammatory process in the eye may lead to severe exophthalmos. DIAGNOSIS (1) DIAGNOSIS (1) Primary hyperthyroidism can be diagnosed by demonstration of : a suppressed TSH concentration and raised thyroid hormone concentration In particular, the finding that TSH is undetectable in one of the modern sensitive assays for this hormone strongly suggests that the symptomatic patient has primary hyperthyroidism. DIAGNOSIS (2) DIAGNOSIS (2) Occasionally, biochemical confirmation of suspected hyperthyroidism will prove more difficult. The total T4 concentration in a serum sample does not always reflect metabolic status, because of changes in binding protein concentration. In pregnancy, high circulating oestrogens cause stimulation of TBG(甲状腺结合蛋白) synthesis in the liver. Total T4 concentrations will be above the reference range, although unbound （free）T4 will be normal (Fig. 1). Congenital TBG deficiency can cause confusion also if a specimen is screened for thyroid hormones, even if thyroid disease is not suspected (Fig. 1). nullDIAGNOSIS(3)DIAGNOSIS(3) Assessment of measurement of free-T4 and TSH. Free-T4 measurement could be used as first-line tests of thyroid dysfunction. TSH measurement is sometimes better，because TSH secretion is very sensitive to changes in free T4. Free T4 analyses are invaluable in diagnoses where binding proteins are altered (Table 1).null DIAGNOSIS (4) DIAGNOSIS (4) In T3 toxicosis T4 concentration is found to be within the reference range. T3 concentration is elevated. TSH is undertectable.nullTREATMENT (1)TREATMENT (1) Antithyroid drugs (such us carbimazole). These are of most use in the younger patient. Radioiodine. Therapy with sodium 131I is commonly used in older patients. Most will eventually require replacement thyroxine. Thus 'thyroid function tests' should be checked regularly to detect developing hypothyroidism. TREATMENT (2) --Surgery. TREATMENT (2) --Surgery. Many patients who have subtotal thyroidectomy（甲状腺切除术） may later require thyroxine replacement. Occasionally the parathyroids (甲状旁腺) may be damaged and the patient may become hypocalcaemic（低血钙的） post-operatively due to lack of PTH（甲状旁腺激素）. TREATMENT (3)TREATMENT (3) Thyroid function tests are important in the monitoring of all three treatments. In these circumstances it must be remembered that it takes a number of weeks before the tissue effects of thyroid hormones accurately reflect the concentration in the serum. SUMMARY--HyperthyroidismSUMMARY--Hyperthyroidism Autoimmune disease is the commonest cause of hyperthyroidism. Diagnosis is confirmed by suppressed TSH and elevated T4 in a serum specimen, although T3 concentration, free hormone levels and bonding protein status may all be needed in difficult situations. The management of hyperthyroidism is by antitbyroid drugs, radioiodine therapy or partial thyroidectomy. TSH and T4 are used to monitor therapy after all of these treatments.