Hypo/Hyper Thyroidism, Addison's, Cushing's

Endocrine system

Plays a vital role in metabolism, cellular interactions, growth, aging, reproduction, and reaction to adverse conditions.

Thyroid gland

A butterfly-shaped endocrine gland located in the lower neck in front of the trachea. 

What three hormones does the thyroid secrete? 

Thyroxine (T4), Triiodothyronine (T3), and Calcitonin. 

What organ causes the thyroid to secrete hormones? 

The pituitary gland.

Where are the parathyroid glands located? 

On the back of the thyroid gland. 

Parathyroid glands

Secretes parathyroid hormones which regulate calcium absorption.

TSH

A hormone secreted from the pituitary gland that releases thyroid hormones. TSH levels increase when thyroid hormone level is low, and decreases when thyroid hormone levels are high.

Calcitonin

Secreted in response to high plasma calcium level and increases calcium deposit into the bone. 

What diagnostics can analyze thyroid function? 

TSH, T3 and T4, radioactive iodine therapy, biopsy, thyroid scan. 

_ is needed to make T3 and T4. 

Iodine

Hypothyroidism presents with _ T3 and T4 levels. 

Low

Hyperthyroidism presents with _ T3 and T4 levels. 

High

Hyperthyroidism

Hyperactivity of the thyroid gland with increase in synthesis and release of thyroid hormones.

What are some common causes of hyperthyroidism? 

Grave’s disease, Toxic multinodular goiter, toxic adenoma, pituitary tumor, and elevated iodine.  

Grave’s disease

Autoimmune disorder with hyperthyroidism because thyroid is stimulated by globulins. 

What is the age range of hyperthyroidism? 

20-40, more common in women. 

What are the clinical manifestations of hyperthyroidism? 

Weight loss, anxious, restless, irritable, fine tremors of the hands, diarrhea, increased appetite, heat intolerance with increased sweating, goiter, thin skin and hair, tachycardia, and palpitations. 

What are the symptoms of Grave’s disease? 

The same manifestations of hyperthyroidism, with bulging eyes.  

What are the lab findings for hyperthyroidism? 

Low TSH, elevated T4, and high radioactive iodine uptake. 

How is hyperthyroidism treated? 

Treatment is based on relieving symptoms and reducing thyroid hyperactivity. Antithyroid agents, radioactive iodine, surgery, and beta-blockers are commonly given. 

Thyroid storm

A form of severe hyperthyroidism, can be fatal if untreated.

What can cause a thyroid storm? 

Stress, injury, infection, surgery, DKA, abrupt withdrawal of antithyroid medications.  

What are the clinical manifestations of a thyroid storm? 

High fever, extreme tachycardia (>130bpm), exaggerated symptoms of hyperthyroidism, altered neuro or mental state.  

What are nursing interventions for post-thyroidectomy? 

Maintain patent airway, keep patient in semi-fowlers, support patients head with pillows, and provide pain medications. 

What are some post-op complications of a thyroidectomy? 

Tetany, Chvostek and Trousseau sign (hypocalcemia signs), injury to laryngeal nerve which may impact vocal cords. 

What are nursing interventions for hyperthyroidism patients? 

Maintain adequate cardiac output, improve nutritional status (high iodine foods, encourage small frequent meals, high carb high protein), enhance coping measures, improve self-esteem, maintain normal body temp., monitor for complications, patient education. 

What are some geriatric considerations for hyperthyroidism? 

May present with vague and nonspecific signs, patient may complain of muscle weakness, beta-blockers should be used with caution due to increased risk of heart failure. 

Hypothyroidism

Results from suboptimal levels of thyroid hormone.

What may cause hypothyroidism? 

Autoimmune thyroiditis (Hashimoto disease) and patients who had hyperthyroidism but has had treatment for it (surgery, radioiodine, etc.).  

What are the lab findings for hypothyroidism? 

Low iodine, low T4, high TSH. 

What are the clinical manifestations of hypothyroidism? 

Fatigue and lethargy, weight gain, cold intolerance, dry skin, bradycardia, hair loss, constipation. 

Myxedema coma

A rare life-threatening condition which may result from missing a thyroid replacement medication dose, systemic disease, or use of opioids. 

What are the symptoms for myxedema? 

Initially depression, diminished cognitive status, lethargy, and somnolence, lethargy increases into stupor, respiratory drive is depressed, coma.  

How is hypothyroidism managed? 

Objective is to restore a normal metabolic state by replacing the missing hormone. Drug of choice is synthetic levothyroxine. 

What are some geriatric considerations with hypothyroidism? 

Prevalence increases with age, symptoms are subtle, management is poorly adhered to requiring periodic monitoring of TSH levels.

Addison’s disease

The result of dysfunction of the hypothalamus-pituitary gland-adrenal gland feedback loop, resulting in insufficient production of steroids by the adrenal glands. Lack of steroids, cortisol, and aldosterone.

What causes Addison’s disease? 

Most common cause is autoimmune disorder, but tuberculosis and histoplasmosis are also associated. Surgical removal of both adrenal glands, certain meds, metastatic cancers, and secondary adrenal insufficiency.  

What are the clinical manifestations of Addison’s disease? 

Muscle weakness, low BP, hypoglycemia, lethargy, anorexia, weight loss, nausea and vomiting, fatigue, hyperpigmentation of the skin and mucous membranes. Increase excretion of sodium, chloride, and water, with increased retention of potassium.  

What are the lab findings for Addison’s disease? 

Hypoglycemia, hyperkalemia, hyponatremia, and leukocytosis. Diagnosis is confirmed by lab results. 

How is Addison’s disease treated? 

Fluids and IV hydrocortisone, glucose, electrolytes, replacement of any missing hormones. 

What are the nursing interventions for Addison’s disease? 

Restore fluid balance, improve activity tolerance, and monitor for Addisonian Crisis.

Addisonian Crisis

Can happen when suddenly stopping steroids, high stress (body lacks cortisol and stress uses cortisol). Symptoms involve Addison’s symptoms becoming suddenly significantly worse. 

What should you educate an Addison’s disease patient on? 

S/S of Addisonian crisis, importance of consistently taking meds, avoid stress of strenuous exercise, corticosteroid dosage will need to be increased during high stress.  

Cushing’s syndrome

Cortisol level is high.

What causes Cushing’s syndrome? 

Excessive adrenocortical activity or corticosteroid medications. 

What are the clinical manifestations of Cushing’s syndrome? 

Central-type obesity w/buffalo hump, heavy trunk and thin extremities, fragile and thin skin, bruising, weakness, sleep disturbances, osteoporosis, muscle wasting, hypertension, moon face, acne, hyperglycemia, weight gain, infection, slow healing, sodium retention, hypokalemia.

What are the diagnostic findings for Cushing’s syndrome? 

Serum cortisol, urinary cortisol, and low-dose dexamethasone suppression tests. Two of these three tests need to be abnormal to diagnose Cushing’s disease.  

What is the treatment for Cushing’s patients? 

Hypophysectomy (for pituitary tumor producing so much ACTH), will need steroids and thyroid hormones after. Or Adrenalectomy, may need steroids so the body can adjust after surgery.  

What are the nursing interventions for Cushing’s patients? 

Maintaining adequate cardiac output, decreasing risk of injury and infection, promoting skin integrity, improving body image and coping, monitoring for potential complications (Addisonian crisis), patient education.