Introduce R. Gholamnezhad Lecturer of school of nursing & midwifery of Iran university Ph.D student tof Immunology, Sh School of medical sciences of Isfahan university E-Mail: Gholami278@gmail. Com
Interpreting of thyroid function tests
Scope The detection of thyroid dysfunction in adults (individuals 19 years of age and over) Monitoring adult patients treated for thyroid Monitoring adult patients treated for thyroid function disorders.
Scope Routine thyroid function testing is not recommended in asymptomatic adults. However, testing may be indicated when non specific signs and symptoms are present in patients at risk for thyroid disease
Risk factors for thyroid disease personal history of thyroid disease strong family history of thyroid disease diagnosis of autoimmune disease past history of neck irradiation drug therapies such as lithium and amiodarone women over age 50 elderly patients women 6 weeks to 6 months post partum
Diagnosis/Investigation Hypothyroidism Weight gain Hair loss Lethargy Menstrual M t lirregularities iti (menorrhagia) Cognitive impairment Depression Constipationp Goitre Dry skin Cold intolerance Hyperthyroidism Weight loss Hair loss Palpitations /Tachycardia / Atrial fibrillationill Menstrual irregularities (amenorrhea / oligomenorrhea) Widened pulse pressure Nervousness and tremor Muscular weakness Goitre Heat intolerance, diaphoresis, clammy hands Hypertension
point Measurement of TSH has become the principal test for the evaluation of thyroid function in most circumstances. A TSH value within the reference interval excludes majority of cases of primary overt thyroid disease. If TSH is abnormal, confirm the diagnosis with free T4 (ft4)
Interpreting of thyroid function tests
HPT Axis
Normal TSH = 0/4 4/5 mu/l T3 = 87 180 ng/dl T4 = 5/6 13/7 mcg/dl FT3= 230 420 Pg /dl FT4 = 0/8 1/5 ng/dl T3 T4 TSH
Hyperthyroidism T3 T4 TSH
Hypothyroidism TSH T3 T4
Please before sampling NOTE: You do not have to fast, but because of the influence of turbidity caused by eating fat on the test results, at least 3 hours before the test, do not eat food. Up to 2 weeks after surgery to avoid these tests. Use of contraceptive pills can increase the hormones. Concentration of thyroid hormones in the summer is 20% lower than winter. Sampling is not done between 16 18 hours.
1 Low TSH Raised FT3 or FT4 Common causes: Primary hyperthyroidism Graves' disease, multinodular goitre, toxic nodule. Relatively common causes with low radio iodine uptake: Transient thyroiditis (postpartum, post viral, De Quervain's thyroiditis). Rare with a low radio iodine uptake: Thyroxine ingestion. Ectopic p thyroid tissue. Iodine induced. Amiodarone therapy. Rare with a positivepregnancy pregnancy test: Gestational thyrotoxicosis with hyperemesis gravidarum. Hydatiform mole. Rare: Familial TSH receptor mutation.
2 Common causes: Subclinical hyperthyroidism. Thyroxine ingestion. Low TSH Normal FT3 or FT4 Rare causes: Steroid therapy. Dopamine and dobutamineinfusion. Non thyroidal illness.
3 Common C causes: Non thyroidal illness. Recent treatment for hyperthyroidism. Low TSH Low FT3 or FT4 Rare causes: Pituitary disease. Congenital TSH or TRH deficiencies
4 Common causes: Chronic autoimmune thyroiditis. Following g radio iodine. Following thyroidectomy. Transient thyroiditis hypothyroid phase. Raised TSH Low FT4 or FT3 Rare causes (anti TPO negative): Following external beam radiotherapy to the neck. Drugs amiodarone, lithium, interferons, interleukin 2. Iodine deficiency. Congenital causes: Congenital causes: Thyroid dysgenesis. Iodine transport defects. TSH receptor defects. TSH resistance.
5 Common causes: Subclinical autoimmune hypothyroidism. Raised TSH Normal FT3 or FT4 Rare causes: Drugs amiodarone, sertraline, colestyramine. Recovery y phase after non thyroidal illness. Heterophile (interfering) antibody. Congenital causes: Congenital causes: TSH receptor defects. TSH resistance
6 Rare causes: Amiodarone. Interfering antibodies. Familial. l TSH secreting pituitary tumour. Acute psychiatric illness Normal or Raised TSH Raised FT3 or FT4
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