Thyroid Disorders Flashcards
Hypothyroidism TSH, T3 and T4 levels
High TSH
Low T3 and T4
Hyperthyroidism TSH, T3 and T4 levels
Low TSH
High T3 and T4
Goiter
Occurs when the thyroid gland is unable to secrete enough thyroid hormone to meet metabolic needs, so it becomes larger.
Endemic Goiter
Caused by lack of iodine in the diet.
Sporadic Goiter
Related to ingestion of large amounts of certain drugs and foods.
Goiter Sequela
Monotone voice
Dysphagia
Tracheal compression
Goiter Labs
T3, 4 and TSH are usually normal
Goiter Tx
reduce hyperplasia and correct underlying dysfxn.
Fine needle aspiration for fast growing goiters
Surgery for large goiters
Hypothyroidism epidemiology
3-5% of population has some form
Women > men
Increases with age
Most common cause = hashimotos thyroiditis
Primary hypothyroidism
Iodine deficiency Autoimmune: Hashimotos Post partom thyroiditis Drug induced Normal aging
Secondary Hypothyroidism
Neoplasm Surgery Post partom necrosis Cushings Radiation
Tertiary Hypothyroidism
Hypothalamus dysfxn
Hemochromatosis
Sarcoidosis
Hypothyroidism History
fatigue, weakness, lethargy
Cold intolerance
Myalgias, arthralgias
Hair loss, menstrual irregularities
Hypothyroidism physical findings
Dry, course skin and brittle nails Hoarse voice Periorbital edema Delayed reflexes Bradycardia
Hypothyroidism Tx
> 50 + CVD = Levothyroxine .025 - .05 mg/day
>50 NO CVD = .075 mg/day
Hypothyroidism monitoring
If hypothalamic-pituitary axis intact: TSH measurements
W/ Pituitary insufficiency: T3 and T4 up to 1.4 and .5 ng/dl
Hashimotos Thyroiditis
Most ommon
AKA chronic lymphocytic thyroiditis
Associated with non-hodgkins lymphoma
Hashimotos epidemiology
Autoimmune and genetic
5-10x more common in women
Usually occurs between 30 and 60
Hashimotos Dx
Anti-thyroid peroxidase antibodies
Goiter, low hormone levels
Hashimotos S/S
Painless goiter
Fatigue, weakness, weight gain
Fullness in throat, neck pain
Low grade fever
Hashimotos Tx
Thyroid hormone replacement
Levothyroxine (synthroid)
Monitor TSH
When to treat subclinical hypothyroidism?
If TSH is >10 mU/L
Myxedema
Tissue proliferation in rxn to increased TSH levels Usually a hx of hypothyroid dz Older adults Droopy eyelids, decreased reflexes **Facial puffiness**
Myxedema Tx
Levothyroxine
Myxedema Coma
True life-threatening emergency
End-stage expression of hypothyroidism
Most frequently seen in elderly women
Myxedema Coma S/S
Coma, hypothermia, CV collapse
Metabolic disorders
Myxedema Coma Tx
Supportive measures
Correct CV and hemodynamic abnormalities
Prevention!
Certinism
Severely stunted mental and physical growth
Usually due to maternal hypothyroidism
Severely delayed puberty
Infertility
Cretinism Tx
Thyroid replacement
Hyperthyroidism
AKA Thyrotoxicosis
102 cases in 1,000 each year
Most common cause is Grave’s
Most common in women 20-40
Hyperthyroidism Symptoms
Nervousness, diaphoresis
heat intolerance
Palpitations, fatigue, weight loss
Frequent bowel movements
Hyperthyroidism Signs
Tachycardia Goiter, skin changes Pretibial myxedema Tremor Exopthalmos Lid Lag Osteoporosis
Hyperthyroidism Lab Findings
Low TSH
Increased T3 and T4
Tx for grave’s or toxic goiter
Methimazole (Tapazole) 5-15 mg/day Propylthiouracil (PTU) 100-150 mg/day radioactive iodine Tx Surgical Tx Propranolol (For less severe hyperT)
Radioactive iodine treatment
Permanent cure for hyperthyroidism
Hyperthyroid Surgery can result in?
Hypothyroidism
Severed recurrent laryngeal nerve
Grave’s Disease
Organ-specific autoimmune disorder
Body produces anti-TPO, anti-TG and TSI
TSI
Thyroid Stimulating Immunoglobulin
Acts as a TSH agonist
Graves epedemiology
Females 4:1
Age 20-50
Spontaneous remission in 1/4 of pts
Graves Tetrad of symptoms
Nontender, smooth symmetric thyroid enlargement
Hyperthyroid state
Exopthalmos
Pretibial Myxedema
Other Graves S/S
Extremely thin digits
Excess sweating
Flat affect, weakness, Afib
Graves Dx
Most specific = ELISA for TSHR-Ab
Evelates TSI
Radioactive iodine uptake
Graves Tx
Methimazole (Tapazole) Propylthiouracil (PTU) Beta Blockers Radioactive Iodine and Steroids Surgery
Multinodular Goiter
“Plummers Disease”
Characterized by functionally autonomous nodules
Older people, iodine insufficiency
Multinodular Goiter Dx
Decreased TSH
Elevated T3, T4
Thyroid scan shows multiple functioning nodules
Factitous Hyperthyroidism
Ingestion of levothyroxine by eithyroid individuals
Health care workers, dieters, body builders….
Attempt to lose weight
T3 and 4 are elevated, Decreased TSH
Thyroid Storm
Life-threatening crisis
Hyperthyroidism
Stress, infxn, DKA, Trauma
Thyroid Storm S/S
Very febrile
Cardiovascular Effects
CNS effect
N/V
Thyroid Storm Tx
Peripheral cooling Replace fluids, glucose, electrolytes Propranolol Glucocorticoids Propylthiouracil and Methimazole
Thyroiditis
Similar to hyperthyroidism
Leakage of thyroid hormone
RAIU is Low
What differentiates thyroiditis from Hyperthyroidism?
RAIU is Low
Acute Thyroiditis
Rare complication of septicemia Fever, skin redness **Tender Thyroid** Treat with IV Abx I&D of gland may be required
Subacute Thyroiditis
Secondary to viral infxn
Fever, anterior neck pain
Exquisitely tender thyroid
NO RAIU
Postpartum Thyroiditis
Occurs in 5-10% of women post-partum
3-12 months post-delivery
Eventually resolves
25-30% will develop hypothyroid within 5 yrs
Postpartum Thyroiditis S/S
Thyroid gland is NONtender
Low uptake of RAI
Postpartum Thyroiditis Tx
Propranolol
Levothyroxine if hypothyroidism develops
Iodine Induced thyroiditis
Jod-Basedow
Contrast agents for angiography or CT
Amiodarone Induced Thyroiditis
Amio is iodinated
Can occur in normal pt’s or pt’s w/ thyroid dz.
Riedel’s Struma
Chronic Thyroiditis
Rare
Thyroid gland is stony hard and adheres to surrounding tissue.
Tx with steroids, tamoxifen
Thyroid Nodules
Most often a benign neoplasm
Usually solitary
Often painless
Appear cold on thyroid scan
Solitary Thyroid Nodule
Usually benign and occurs in most everyone by death.
Hard, fixed nodule
Lymphadenopathy
Cold nodule on scan
T of F: A hot nodule is suspicious for Cancer.
False. A cold nodule is suspicious for cancer.
Hot nodules are very low risk for cancer
Thyroid Cancer
1% of malignant neoplasias
Painless swelling of thyroid
Normal thyroid fxn test
Scan usually shows cold lesions
Papillary Carcinoma
Most common Slow growing Generally asymptomatic Painless neck mass Elevated thyroglobulin levels Good prognosis
Follicular Carcinoma
Slow growing
Regional nodes
Spread to lung or bone
Medullary Carcinoma
Familial affiliation
C-cells of thyroid
Nodule in upper half of thyroid
Calcitonin is tumor marker
