Metabolism and Thermoregulation: Hypothyroidism and Hyperthyroidism
Metabolism
Metabolism: processes of biochemical reactions occurring in the body’s cells; necessary for energy production,
cellular repair, and maintain life
Hormones: chemical messengers that are secreted by various glands and exert controlling effects on the cells;
regulates growth, reproduction, fluid and electrolyte balance, gender differentiation
Thyroid Gland: Hormones; affect every system in the body
o Thyroxine (T4) converts into Triiodothyronine (T3) at target tissue
Maintains metabolic rate and growth and development of all tissues; T3 and T4 are secreted in
response to thyroid-stimulating hormone; glucose tolerance decreases with thyroid issues
Avoid Aspirin: binds to protein; does not allow T3 to bind to protein
o Calcitonin: maintains blood calcium levels by decreasing bone resorption and decreasing resorption of
calcium in the kidneys whenever levels of blood calcium levels are elevated
o Iodine: essential for synthesis of hormones; hormones attach to carrier proteins- malnutrition: increased
% of free thyroid hormone; increased risk for hyperthyroidism
Thyroid Disorder Related to Age: increase in fibrosis and nodularity; decrease in gland activity: lower basal
metabolic rate, increased chance of hypothyroidism, palpable nodes on palpation
Interrelated Concepts
o Acid-Base Balance: metabolic acidosis (DKA) in DM1
o Perfusion: Myxedema: long-standing untreated hypothyroidism
Fluid retention, edema, dyspnea, profound bradycardia, metabolic disorders, cardiovascular
collapse
Client has history of untreated or undiagnosed hypothyroidism; observes: widespread
edema (esp. around eyes, hands, feet), altered LOC, slow pulse, and decreased BP
o Oxygenation: Ascites: accumulation of fluid in abdominal cavity
o Stress and Coping: feeling of powerlessness and loss related to diabetes
Graves Disease: thyroid condition that results in hyperthyroidism; autoimmune; autoimmune version of
hyperthyroidism; eye changes can be irreversible
o Symptoms: overactive thyroid: increased appetite, weight loss, hypermotile bowels, diarrhea, heat
intolerance, insomnia, increased sweating, fatigue, hand tremors, changes in menstruation to
amenorrhea, older adult: a. fib, angina, CHF
o Enlarged thyroid gland- goiter, manifestations of hyperthyroidism
o Proptosis: forward displacement of the eye; Exophthalmos: forward protrusion of the eye; fat deposits
Accumulation of inflammation by-products; sclera is visible above the iris; retracted upper
eyelids; unblinking stare, increased pressure on optic nerve (#2; sensory; visual acuity/field test)
Blurred vision, diplopia, eye pain, lacrimation, photophobia, inability to close the eyelids (cornea
dryness, irritation, infection, ulceration)
Toxic Multinodular Goiter: thyroid tumor; small, discrete, independently functioning nodules in thyroid gland
tissue; genetic mutation suspected
o Most common: postmenopausal women; presents with hyper- and hypothyroidism
Excess TSH Stimulation: overproduction of TSH by pituitary gland stimulates overproduction of TH
o Results from pituitary adenoma; very rare; brain tumor
Thyroiditis: inflammation of thyroid gland; results from viral infection
o Acute inflammation, increased TH, acute disorder (hyperthyroidism) can become chronic: hypothyroid
state, repeated infections, destroyed thyroid tissue
Prevention and Risk Factors
o Thyroid disorders do not have modifiable risk factors; related to other autoimmune disorders (DM1)
Regular physical exams: detect enlarged thyroid, lab testing may detect abnormal thyroid levels
, EXEMPLAR: HYPERTHYROIDISM
What is it? Thyrotoxicosis
Disorder caused by excessive delivery of TH to peripheral tissues
Affects all major organ systems
What causes it? Autoimmune (Graves Disease)
Excess secretion of thyroid-stimulating hormone (TSH): toxic multinodular goiter
* SEE ABOVE* Excess intake of thyroid medication
How will it Increased appetite, weight loss increased metabolic demand
present? Hypermotile bowels: increased peristalsis, bloating, pain; diarrhea
Increased heart rate, stroke volume, cardiac output; carbohydrate, lipid, protein
metabolism
Heat intolerance
Insomnia (no downtime for body systems)
Palpitations
Increased sweating; smooth, warm skin
Fine hair, hair loss (head-to-toe)
Emotional lability
Risk factors: Women increased risk
Genetic factors: Graves Disease
Increased Iodine intake
How is it Elevated TH (both T3 and T4)
diagnosed? Thyroid Antibody Test (TA): elevated in Graves Disease
TSH Levels high- TSH Test (sensitive assay): determines pituitary or thyroid dysfunction
pituitary T4 & T3 Test: elevated in thyroiditis, hyperthyroidism
malfunction T3 Uptake Test: mixed with radioactive T3; elevated with hyperthyroidism
RAI Uptake Test: thyroid scan; seen in Graves Disease
Elevated thyroid Thyroid Suppression Test: RAI and T4 tested; takes TH for 7-10 days and tested again
with normal TSH
Treatment: Pharmacology Therapy: antithyroid medication reduces TH production, beta-blocker
Radioactive Iodine Therapy (RAI): contraindicated for pregnant women; can develop
hypothyroidism: measure pulse rates, notify HCP of HR >100
Surgery: thyroidectomy; partial or total
Complications: Thyroid Storm: thyroid crisis; extreme state of hyperthyroidism; common with
A: airway: untreated hyperthyroidism (Graves Disease), and stressors: DKA, infection, trauma,
edema; surgery on gland
hoarseness ▫ Symptoms: hyperthermia (102-106 F), tachycardia, significant systolic
B: breathing hypertension, GI symptoms: abdominal pain, vomiting, diarrhea; agitation,
C: circulation- restlessness, tremors, confusion, psychosis, delirium, seizures
neutral; watch ▫ Treatment: cooling, replace: fluids, electrolytes, glucose; relieve respiratory
for bleeding distress, stabilize cardiovascular function, reduce TH synthesis and
C: calcium: secretion; DO NOT USE ASPIRIN, DO NOT INDUCE SHIVERING
hypocalcemia; ▫ Multi-system effects; ABCs and Maslow’s for priority care
tingling around Goiter: trouble swallowing; needs to be removed
mouth, fingers,
toes
Nursing Care: Education regarding disease process; treatment; posttreatment care
Recognize the impact of increased metabolism rates; increased cardiac function, inability
to keep up with nutritional needs; inability to concentrate on information presented
Surgery: trach kit/set up at bedside for potential for swelling
Metabolism
Metabolism: processes of biochemical reactions occurring in the body’s cells; necessary for energy production,
cellular repair, and maintain life
Hormones: chemical messengers that are secreted by various glands and exert controlling effects on the cells;
regulates growth, reproduction, fluid and electrolyte balance, gender differentiation
Thyroid Gland: Hormones; affect every system in the body
o Thyroxine (T4) converts into Triiodothyronine (T3) at target tissue
Maintains metabolic rate and growth and development of all tissues; T3 and T4 are secreted in
response to thyroid-stimulating hormone; glucose tolerance decreases with thyroid issues
Avoid Aspirin: binds to protein; does not allow T3 to bind to protein
o Calcitonin: maintains blood calcium levels by decreasing bone resorption and decreasing resorption of
calcium in the kidneys whenever levels of blood calcium levels are elevated
o Iodine: essential for synthesis of hormones; hormones attach to carrier proteins- malnutrition: increased
% of free thyroid hormone; increased risk for hyperthyroidism
Thyroid Disorder Related to Age: increase in fibrosis and nodularity; decrease in gland activity: lower basal
metabolic rate, increased chance of hypothyroidism, palpable nodes on palpation
Interrelated Concepts
o Acid-Base Balance: metabolic acidosis (DKA) in DM1
o Perfusion: Myxedema: long-standing untreated hypothyroidism
Fluid retention, edema, dyspnea, profound bradycardia, metabolic disorders, cardiovascular
collapse
Client has history of untreated or undiagnosed hypothyroidism; observes: widespread
edema (esp. around eyes, hands, feet), altered LOC, slow pulse, and decreased BP
o Oxygenation: Ascites: accumulation of fluid in abdominal cavity
o Stress and Coping: feeling of powerlessness and loss related to diabetes
Graves Disease: thyroid condition that results in hyperthyroidism; autoimmune; autoimmune version of
hyperthyroidism; eye changes can be irreversible
o Symptoms: overactive thyroid: increased appetite, weight loss, hypermotile bowels, diarrhea, heat
intolerance, insomnia, increased sweating, fatigue, hand tremors, changes in menstruation to
amenorrhea, older adult: a. fib, angina, CHF
o Enlarged thyroid gland- goiter, manifestations of hyperthyroidism
o Proptosis: forward displacement of the eye; Exophthalmos: forward protrusion of the eye; fat deposits
Accumulation of inflammation by-products; sclera is visible above the iris; retracted upper
eyelids; unblinking stare, increased pressure on optic nerve (#2; sensory; visual acuity/field test)
Blurred vision, diplopia, eye pain, lacrimation, photophobia, inability to close the eyelids (cornea
dryness, irritation, infection, ulceration)
Toxic Multinodular Goiter: thyroid tumor; small, discrete, independently functioning nodules in thyroid gland
tissue; genetic mutation suspected
o Most common: postmenopausal women; presents with hyper- and hypothyroidism
Excess TSH Stimulation: overproduction of TSH by pituitary gland stimulates overproduction of TH
o Results from pituitary adenoma; very rare; brain tumor
Thyroiditis: inflammation of thyroid gland; results from viral infection
o Acute inflammation, increased TH, acute disorder (hyperthyroidism) can become chronic: hypothyroid
state, repeated infections, destroyed thyroid tissue
Prevention and Risk Factors
o Thyroid disorders do not have modifiable risk factors; related to other autoimmune disorders (DM1)
Regular physical exams: detect enlarged thyroid, lab testing may detect abnormal thyroid levels
, EXEMPLAR: HYPERTHYROIDISM
What is it? Thyrotoxicosis
Disorder caused by excessive delivery of TH to peripheral tissues
Affects all major organ systems
What causes it? Autoimmune (Graves Disease)
Excess secretion of thyroid-stimulating hormone (TSH): toxic multinodular goiter
* SEE ABOVE* Excess intake of thyroid medication
How will it Increased appetite, weight loss increased metabolic demand
present? Hypermotile bowels: increased peristalsis, bloating, pain; diarrhea
Increased heart rate, stroke volume, cardiac output; carbohydrate, lipid, protein
metabolism
Heat intolerance
Insomnia (no downtime for body systems)
Palpitations
Increased sweating; smooth, warm skin
Fine hair, hair loss (head-to-toe)
Emotional lability
Risk factors: Women increased risk
Genetic factors: Graves Disease
Increased Iodine intake
How is it Elevated TH (both T3 and T4)
diagnosed? Thyroid Antibody Test (TA): elevated in Graves Disease
TSH Levels high- TSH Test (sensitive assay): determines pituitary or thyroid dysfunction
pituitary T4 & T3 Test: elevated in thyroiditis, hyperthyroidism
malfunction T3 Uptake Test: mixed with radioactive T3; elevated with hyperthyroidism
RAI Uptake Test: thyroid scan; seen in Graves Disease
Elevated thyroid Thyroid Suppression Test: RAI and T4 tested; takes TH for 7-10 days and tested again
with normal TSH
Treatment: Pharmacology Therapy: antithyroid medication reduces TH production, beta-blocker
Radioactive Iodine Therapy (RAI): contraindicated for pregnant women; can develop
hypothyroidism: measure pulse rates, notify HCP of HR >100
Surgery: thyroidectomy; partial or total
Complications: Thyroid Storm: thyroid crisis; extreme state of hyperthyroidism; common with
A: airway: untreated hyperthyroidism (Graves Disease), and stressors: DKA, infection, trauma,
edema; surgery on gland
hoarseness ▫ Symptoms: hyperthermia (102-106 F), tachycardia, significant systolic
B: breathing hypertension, GI symptoms: abdominal pain, vomiting, diarrhea; agitation,
C: circulation- restlessness, tremors, confusion, psychosis, delirium, seizures
neutral; watch ▫ Treatment: cooling, replace: fluids, electrolytes, glucose; relieve respiratory
for bleeding distress, stabilize cardiovascular function, reduce TH synthesis and
C: calcium: secretion; DO NOT USE ASPIRIN, DO NOT INDUCE SHIVERING
hypocalcemia; ▫ Multi-system effects; ABCs and Maslow’s for priority care
tingling around Goiter: trouble swallowing; needs to be removed
mouth, fingers,
toes
Nursing Care: Education regarding disease process; treatment; posttreatment care
Recognize the impact of increased metabolism rates; increased cardiac function, inability
to keep up with nutritional needs; inability to concentrate on information presented
Surgery: trach kit/set up at bedside for potential for swelling
