Thyroid Flashcards
Thyroid hormone regulation
TSH is controlled Thyrotropin releasing hormone made in the hypothalamus
TRH->TSH->T4 and T3
Labs
Free T4 and TSH usually done
Less sensitive T4, T3, free T3, reverse T3
Thyroid hormones regular
Energy, heat production, facilitate development of CNS, growth and puberty, regulate liver proteins, cardiac, neuro, muscle and function
Thyroid dysfunction
Primary-at the gland
Secondary - at the pituitary
Tertiary - at the hypothalamus
Hyperthyroidism causes
Toxic adenoma (seniors)
Toxic multi nodular goiter (seniors)
Painful thyroiditis (viral)
Excessive iodine intake
Excessive thyroid replacement
Hyperthyroidism causes
L131 iodine thyroid gland ablation (destruction)
Total or subtotal thyroidectomy
Other autoimmune
External XRT of the thyroid
Defective thyroid hormone synthesis or iodine deficiency-lithium use
S/S of hyperthyroidism
Weight loss
Nervousness
Irritability
Insomnia
Heat intolerance
Bulging of the eyes
Deepening a voice
Tremors
Muscle weakness
Osteoporosis
Increased sweating
Silky hair
Ridges of nails
Sore throat
Goiter
Tremors
Hyperreflexia
Increase sweating
Silky hair
Ridges in nails
Angina
Tachycardia
Low BP
CHF
Diarrhea
Infertility
S/S of hypothyroidism
Increase weight
Depression
Hypersomnia
Fatigue
Forgetfulness
Inability to concentrate
Mental retardation
Cold intolerance
Puffy eyes
Large tongue
Hearing impairment
Deepening a voice
Sore throat
Goiter
Muscle weakness
Cramps
Muscle pain
Dry skin
Thin hair
Myxedema
Yellow skin
Bradycardia
High BP
Increased LDL
Ascites
Constipation
Infertility
Irregular periods
Hypothyroidism
-Worldwide commonly due to iodine deficiency//In developed countries it’s due to autoimmune hasimotos
-Subclinical- normal free T4, and high TSH-may not have symptoms
-iatrogenic-post radioactive tx or survey for hyperthyroidism, nodules or cancer
RF: family hx, antithyroid antibodies, XRT of head, neck, or chest, autoimmune, age, lithium, amiodarone, iodine
DX; at 35-40 years, high risk factor, women with infertility
Test:TSH, T4, CBC, CMP, BP, lipid, CXR, thyroid US
Meds interaction- Reglan, dopamine, glucocorticoids, NSAIDs, somatostatin, nicotine, Dilantin, amiodarone, lithium
DD: nephrotic syndrome; chronic nephritis, depression, PP thyroiditis, post infection thyroiditis, meds
drugs- levothyroxine 25 mcg per week and titrate until TSH normal, cardiac disease start at 12.5 mcg, severe may need IV
Endocrine referral
Hyperthyroidism
Excess T4 or T3
Types-graves, subacute thyroiditis, toxic multinodular goiter, toxic thyroid adenoma
Due to inappropriate thyroid replacement, excess iodine, pituitary tumor, graves
DX-TSH, T3, T4, radioactive update scan, US thyroid
DD- exogenous thyroid ingestion, hydatiform mole, anxiety, pheochronocytoma, menopause, pregnancy, CA, MG, dopamine, amiodarone, anphetamines, heroin, heparin, methoadone, perphenazine
TX- surgery, drugs or ablation, BB, CCB, PTU or methimazole
When identify an individual from a developed country who has goiter it is important to identify if they have a dietary deficiency of
Iodine
Graves’ disease is caused by
An autoimmune response
In Graves’ disease you would expect
TSH to be decreased
Most serious side effects of PTU and tapazole is
Agranulocytosis
Sally is a 44 year old who thinks she is getting menopause because her menstrual periods are becoming regular. Her major complaint is lack of energy and weight gain. Physical exam reveals dry skin thinning hair, puffy facial appearance enlarged nontender thyroid. Blood pressure is 130/92 heart rate 60 this suggest.
Hypothyroidism
Which of the following thyroid function test must be used in pregnant females to assess thyroid function
Free T4
Which of the following signs most often leads to patients being evaluated for hyperthyroidism
Tremor
Which of the following lab panels represents hypothyroidism
High TSH
Low T4
Low free T4
Which of the focus not a type of thyroid malignancy
Squamous carcinoma
Which of the following is used to differentiate between thyroiditis and non toxic goiter
Thyroid autoantibodies
A 58-year-old woman presents with three month history of fatigue and memory problems for physical exam reveals delayed relaxation of the reflexes and core dry skin. You can start a diagnosis of.
Hypothyroidism
A patient with symptoms of hypothyroidism is likely to have
High TSH
For initial routine screening of hyper or hypo function of the thyroid gland the first diagnostic test is
TSH assay
