Thyroid Flashcards
1
Q
The Hypothalamus secretes:
A
TRH
2
Q
The Anterior Pituitary Secretes
A
TSH
3
Q
Thyoid Gland Secretes
A
T3/T4
4
Q
T3 is more
A
Metabolically active; In liver and gut microbiome
5
Q
T4 is more
A
Abundant (85%)
6
Q
Primary issues of the thyroid indicate issues at:
A
Thyroid gland
7
Q
Secondary issues of the thyroid occur at:
A
Anterior pituitary
8
Q
Tertiary issues of the thyroid occur at:
A
Hypothalamus
9
Q
Primary carrier of T3/T4
A
Thyroid Binding Globulin
-85% of T4
-70% of T3
10
Q
Hyperthyroidism: Signs/Symptoms
A
-Exopthalamos
-Lid lag
-Increased HR
-Warm skin
-Weight loss
-Missed/infrequent periods
-Fatigue: Lack of sleep
11
Q
Hypothyroidism: Signs/Symptoms
A
-Loss of hair in outer 1/3 of eyebrows
-Cold, dry skin
-Cold intolerance
-Weight gain
-Heavy menses: First sign
-Fatigue
12
Q
Thyroxine, Total T4
A
-Total amount of T4: T4 bound to TBG & free T4
-Interference: Altered levels of TBG
13
Q
Thyroxine (Total T4): Newborn*
A
<7ug/dL: Congenital Hypothyroidism
14
Q
Thyroxine (Total T4): Adult
A
<2ug/dL: Myxedema coma possible
>20ug/dL: Thyroid storm possible
15
Q
Thyroxine: increased Levels
A
-Hyperthyroid States:
-Acute Thyroidism
-Pregnancy
16
Q
Thyroxine Decreased Levels
A
Hypothyroid States
17
Q
Free Thyroxine Assay (free T4)
A
One of the best tests of thyroid function
18
Q
T3U Test
A
-Capacity of TBG to bind labeled T3 at unsaturated T4 sites on TBG
19
Q
T3U: Hyperthyroidism
A
-Less open seats
-More T3 at resin column
-Increase in T3 uptake
20
Q
Increased TBG Causes
A
-Pregnancy
-Oral Contraceptives (or estrogen therapy)
-Certain liver conditions
-Less T3U at resin column
21
Q
T3U: Decreased TBG Causes
A
Testosterone Treatment
More T3U at resin column
22
Q
Free Thyroxine Index
A
Corrects TBG alterations
FTI= T4 X T3U
23
Q
Triiodothyronine Tests (T3 by RIA) are used to detect
A
T3 thyrotoxicosis
-Not accurate for hypothyroidism
24
Q
Reflexes
A
-Hypothyroidism: Decreased reflexes
-Hyperthyroidism: Increased reflexes
25
Cholesterol
-Myxedema: Elevated TC (decreased thyroid hormone)
-Hyperthyroidism: low TC (increased thyroid hormone)
26
TSH is important in differentiating:
Primary and secondary hypothyroidism
27
Primary vs. Secondary hypothyroidism
-Primary: Increased TSH
-Secondary: Decreased TSH & T3/T4
28
TSH: Increased TSH
Primary Hypothyroidism
29
Decreased TSH
Secondary Hypothyroidism
30
TRH Assay
Important in differentiating secondary or tertiary hypothyroidism
31
Secondary vs. Tertiary Hypothyroidism
-Secondary: Injected TRH/Low TSH (Anterior Pituitary Issue)
-Tertiary: Inject TRH/High TSH (Hypothalamus Issue)
32
Thyroid Antibodies are most important in determining
Hashimoto’s Thyroditis
33
Thyroid Antibodies
-Anti-TPO* BEST
-Antithyrogloblin Test
34
Thyroid Screening begins at what age?
-Begins at 35 (Every 5 years)
35
Suspected Hypothyroidism: Needed tests for diagnosis
TSH, Free T4, anti-TPO at minimum
36
Hypothyroid Conditions
-Primary Hypothyroidism: Most Common
-Post-therapeutic Hypothyroidism: 2nd MC
-Goitrous Hypothyroidism: Pregnancy, Menopause..
-Secondary Hypothyroidism: Can’t Secrete TSH
37
Primary Hypothyroidism is typically due to:
An autoimmune disease usually as sequela of Hashimoto’s thyroiditis
38
Post-Therapeutic Hypothyroidism is due to:
• Radioactive iodine treatment or surgery for hyperthyroidism
39
Causes of Goitrous Hypothyroidism
- Pregnancy, Menopause, Iodine Deficiency Hashimotos
40
Secondary Hypothyroidism is the failure of:
Anterior Pituitary (Can’t secrete TSH)
41
Tertiary Hypothyroidism is due to a failure of:
Hypothalamus (Decrease in TRH)
42
Congenital Hypothyroidism: Key Signs/Symptoms
• Drooling
• Broad face
• Umbilical hernia, out belly
43
Hypothyroidism: Most Common Symptoms
MC Symptoms (can have 1+ but varies): Weakness/fatigue/lethargy, decreased memory, modest weight gain (10 lbs), coarsening/huskiness of voice, menstrual changes (typically first sign), sensitivity to cold
44
Hypothyroidism: Key Neurological Complications
Neurological Complications: Headaches, bilateral carpal tunnel, symmetrical/primarily sensory peripheral neuropathy
45
Hypothyroidism: Musculoskeletal Complaints
Musculoskeletal: Myalgia (morning stiffness; Affects hips/thighs & shoulders), Arthralgia (spine, hands, knees, hips), muscle spasms
46
Hypothyroidism: Mental Symptoms
Mental: Mental apathy, Drowsiness, Personality changes
47
Myxedema Coma
Myxedema Coma (more serious): Long-standing hypothyroidism, coma with severe hypothermia, areflexia/seizures/respiratory depression
48
Myxadematous Facies
• Large tongue
• Slow, deep-toned speech
• Dry, thick skin
• Puffy hands and face
• Dull facial expression, eyelids droo
49
Congenital Hypothyroidism: Labs
• Increased serum TSH
•T3/ T4 decreased
• ALP decreased
• Cholesterol increased
50
Primary Hypothyroidism: Labs
-Primary Hypothyroidism: T4 decreased T3U decreased, TSH increased
51
Primary Hypothyroidism: Thyroid Labs
-Thyroid: T4 decreased T3U decreased, TSH increased
52
Secondary Hypothyroidism: Labs
-Secondary Hypothyroidism: T4 decreased, T3U decreased, TSH decreased*
53
Hypothyroidism: Cholesterol/Anemia/Enzyme Labs
-Cholesterol: Increased
-Anemia: Any morphological type
-Other: ALP decreased, increased CPK (d/t muscle atrophy, increased AST
54
Hyperthyroidism: Etiologies
1. Toxic diffuse goiter: Autoimmune (Grave’s Disease)
2. Toxic nodular goiter: Plummer’s Disease
3. Thyroiditis Factitial: “Fake”
4. Thyroiditis forms
5. Secondary Hyperthyroidism: Space Occupying Lesion
6. T3 Thyrotoxicosis
7. Thyroid Storm: Emergency
55
Hyperthyroidism: Main Signs/Symptoms
• Nervousness (85%)
• Increased sweating (70%)
• Hypersensitivity to heat (70%)
• Dyspnea (75%)
• Fatigue and weakness (60%)
• Increased appetite (40%)
• Weight loss (50%)
56
Grave’s Disease: Eye Signs
• Lid lag
• Stare
• Exophthalmos
• Increased lacrimation
• Orbital pain
• Ocular muscle weakness
57
Grave’s Disease: Thyroid Dermopathy
• Thyroid dermopathy – lesions of skin due to deposition of hyaluronic acid
58
Primary Hyperthyroidism: Thyroid Labs
• T4: Increased
• T3U: Increased
• TSH: Decreased
59
Primary Hyperthyroidism: Cholesterol
Decreased
60
Hyperglycemia can occur in:
BOTH hyper and hypothyroidism
61
Primary Hyperthyroidism: Antibodies
-Anti-Body Tests: + Thyroid-Stimulating Immunoglobulin (TSIs)**, + TSH receptor antibodies;
-Possible: + TPO, + thyroantibodies
62
Hypothyroidism: Management
Management: Thyroid Hormone for Life
-Referral to endocrinologist
63
Hyperthyroidism: Management
• Iodine in pharmacologic doses
• Antithyroid drugs
• Radioiodine therapy
• Surgery
-Referral to Endocrinologist
64
Euthyroid Goiter
• Enlarged thyroid gland w/o clinical or lab evidence of thyroid dysfunction
-MC during: Pregnancy, Menopause, Puberty
65
Euthyroid goiter: Signs & Symptoms
• Soft, symmetric, smooth goiter
• History of iodine intake or ingestion of goitrogen
66
Euthyroid Goiter: Thyoid Labs
• T4 and T3U normal
• TSH increased
• Thyroid antibodies should be ordered to rule out Hashimoto’s thyroiditis
67
Thyroiditis
• A variety of inflammatory thyroid disorders that can cause thyroid enlargement and atrophy
• May lead to hypothyroidism or hyperthyroidism
68
Subacute Granulomatous Thyroiditis: Signs/Symptoms
• Pain in neck: Radiates to jaws, arms, or chest
• Aggravated by swallowing or turning head
• Low grade fever
• Lassitude, malaise, prostration
-Recent Viral Infection
69
Subacute Granulomatous Thyroiditis: Signs/Symptoms
• Pain in neck: Radiates to jaws, arms, or chest
• Aggravated by swallowing or turning head
• Low grade fever
• Lassitude, malaise, prostration
-Recent Viral Infection
70
Subacute Granulomatous Thyroiditis: Progression
• Hyperthyroidism, phase of mild hypothyroidism, resolution
71
Subacute Granulomatous Thyroiditis: Expected Labs
• ESR, CRP elevated
• T4 increased
• WBC normal or decreased (viral)
• Anti-thyroglobulin antibodies may be present
72
Hashimoto’s Thyroiditis: Signs/Symptoms
• Fullness in throat
• Gland is painless, firm
73
___% of Hashimoto’s will end up with hypothyroid
90%
74
Hashimoto’s Thyoiditis: Early Stages
-Early Stages: T4/TSH normal & high levels of TPO antibodies
75
Hashimoto’s Thyroidism: Thyroid/Cholesterol Labs
(If Hypothyroid)
decreased T3 &T4 /increased TSH
-Cholesterol: Elevated
76
Hashitmoto’s Thyroiditis: Antibodies
Anti-TPO antibodies*, anti-thyroglobulins
77
Hashimoto’s Thyroiditis: IF hyperthyroidism
If hyper: Hashitoxicosis (Low TSH/High T3/T4)
78
Most common form of thyroiditis
Hashimoto’s
79
Hashimoto’s Thyroiditis often presents as:
Asymptomatic diffuse goiter
80
Hashimoto’s is most prevalent in: Gender/Age
-Women
-30-50 years of age
81
“Silent” Lymphocytic Thyroiditis
• Spontaneously resolving hypothyroidism and/or hyperthyroidism associated with pregnancy
• Occurs in about 5-10% of postpartum women
82
Thyoid Neoplasm (Cancer): Signs/Symptoms
• Mass in neck (painless)
• Pain and tenderness are infrequent
• Hard, irregular, fixation of gland to adjacent structures
• Symptoms due to metastasis
-Hoarseness, voice change
83
Thyroid Neoplasm: Lab Findings
• Thyroid function tests usually normal
• Hormone levels normal
• Fine Needle Aspiration (FNA)
• Thyroid scan, sonogram
84
Thyroid Neoplasm: Treatment
• Surgery
• Hormone for life
85
Subclinical Hyperthyroidism: Symptoms
• Asymptomatic or minimal symptoms of hyperthyroidism
86
Subclinical Hyperthyroidism: Labs
Low TSH, normal free T4 and T3 levels
-Hyperglycemia
87
SC Hyperthyroidism is _____ common than SC hypothyroidism
Less
88
SC Hyperthyroidism: Most Common Cause
Administration of thyroid hormone
89
SC Hyperthyroidism: Other Causes
Other causes – developing Grave’s disease, autonomous thyroid nodules
90
SC Hypothyroidism: Symptoms
• No or minimal symptoms suggestive of hypothyroidism
91
SC Hypothyroidism: Labs
• High TSH, normal free T4 and T3 levels
-Hyperglycem
92
______ should be measured in all cases of subclinical hypothyroidism
TPO antibodies
93
SC Hypothyroidism: Screening
-Hypercholesterolemia
-TPO antibodies
-TSH
-Thyroid Hormones
