Hyperthyroidism (overactive thyroid) is a condition caused by too much thyroid hormone in the body. It is also known as thyrotoxicosis.
Description of Hyperthyroidism
The thyroid gland is located in the front of the neck, just below the larynx (voice box). It helps to maintain a healthy metabolism (the process by which foods are transformed into basic elements which can be utilized by the body for energy or growth) by producing and releasing iodine-containing hormones called thyroxine (T4) and triiodothyronine (T3).
T4 helps in regulating the body's growth, metabolism, digestion, body temperature and heartbeat. When the body produces too much of this hormone, it causes exaggerated bodily responses.
Causes and Risk Factors of Hyperthyroidism
The causes of hyperthyroidism include:
* Grave's disease, also known as toxic diffuse goiter (enlargement of the thyroid gland) and is the most common form of hyperthyroidism (in about 75 percent of all cases) affecting the entire thyroid gland. Grave's disease is considered an autoimmune disorder (a condition in which the body's immune system develops antibodies against its own thyroid gland cells).
* Plummer's disease (involves a single mass or adenoma)
* pituitary tumors
* thyroiditis (inflammation of the thyroid gland caused by excessive amounts of thyroid hormone leaking out of the thyroid gland and into the blood)
* too much thyroid hormone medication
* excessive dietary intake of iodine (found in seaweed and liver)
Symptoms of Hyperthyroidism
The symptoms of hyperthyroidism may include:
* goiter (enlarged thyroid gland)
* mental impairment, memory lapses, diminished attention span
* trembling hands
* itchy skin
* unexplained weight loss despite increased appetite
* heart palpitations
* heat intolerance
* increased sweating
* muscle weakness
* hair loss
* increase in bowel movements
* decrease in menstrual periods
* eye irritation
* protruding eyeballs (Grave's disease only)
If the person is exhibiting extreme irritability, high blood pressure, rapid heart rate, vomiting, fever up to 106, and delirium, they may have thyroid storm. Thyroid storm is a complication of Grave's disease that comes on suddenly and may be caused by a stressful event, such as injury, surgery or infection. Immediate treatment is necessary.
Diagnosis of Hyperthyroidism
The diagnosis of hyperthyroidism is often obvious from the patient's symptoms and appearance. However, to confirm the diagnosis, blood tests may be done for TSH (thyroid-stimulating hormone) or other thyroid hormones.
Additionally, the doctor may do a thyroid scan. The thyroid scan, or iodine uptake test, involves the patient swallowing a solution containing radioactive iodine. The physician then uses a scanning device to measure the amount of iodine that has been absorbed by the thyroid; an elevated level further confirms that the gland is overactive.
Treatment of Hyperthyroidism
There is no one treatment that is best for all patients with hyperthyroidism. Many factors will influence the doctor's choice of treatment, including the patient's age, the form of hyperthyroidism, the severity of the disease and other medical conditions which may be affecting the patient's health.
Currently, there are three principal ways to treat hyperthyroidism: drug therapy, radioactive iodine therapy and surgery.
Drug therapy includes using two types of drugs to control the hyperthyroidism. Initially, the doctor will prescribe either methimazole (Tapazole) or propylthiouracil (PTU) pills which are antithyroid agents. These drugs block the amount of thyroid hormone in the blood and make it more difficult for iodine to get into the thyroid gland.
Although these drugs have blocked the amount of thyroid hormone in the blood, there are still high levels of circulating thyroid hormone in the blood. To combat this, the doctor may also prescribe beta-blocker drugs, such as propranolol (Inderal), to block the action of the circulating thyroid hormone.
Most people with classic hyperthyroidism rarely need hospitalization. Critically ill patients, those with extreme manifestations of thyrotoxicosis plus a significant concurrent illness, require inpatient acute care on a medical unit.
- Heart failure: chronic
- Psychosocial aspects of care
- Patient Assessment Database
- Data depend on the severity/duration of hormone imbalance and involvement of other organs.
- Nervousness, increased irritability, insomnia
- Muscle weakness, incoordination
- Extreme fatigue
- Chest pain (angina)
- Dysrhythmias (atrial fibrillation); gallop rhythm, murmurs
- Elevated BP with widened pulse pressure
- Tachycardia at rest
- Circulatory collapse, shock (thyrotoxic crisis)
- Urinating in large amounts
- Stool changes; diarrhea
Recent stressful experience, e.g., emotional/physical
Emotional lability (mild euphoria to delirium); anxiety/depression
- Recent/sudden weight loss
- Increased appetite; large meals, frequent meals; thirst
- Enlarged thyroid; goiter
- Nonpitting edema, especially in pretibial area
- Rapid and hoarse speech
- Mental status and behavior alterations, e.g., confusion, disorientation, nervousness, irritability, delirium, frank psychosis, stupor, coma
- Fine tremor in hands; purposeless, quick, jerky movements of body parts
- Hyperactive DTRs
- Paralysis (thyrotoxic hypokalemia)
Orbital pain, photophobia (eye movement)
- Increased respiratory rate, tachypnea
- Breath sounds: Crackles, wheezes (pulmonary edema associated with thyrotoxic crisis)
- Heat intolerance, excessive sweating
- Allergy to iodine (may be used in testing)
- Elevated temperature (above 100°F), diaphoresis
- Skin smooth, warm, and flushed; hair fine, silky, straight
- Exophthalmos, lid retraction; conjunctival irritation, tearing
- Pruritic, erythematous lesions (often in pretibial area) that become brawny
- Decreased libido
- Hypomenorrhea, amenorrhea
- Family history of thyroid problems
- History of hypothyroidism, thyroid hormone replacement therapy or antithyroid therapy, premature withdrawal of antithyroid drugs, recent partial thyroidectomy
- History of insulin-induced hypoglycemia, cardiac disorders or surgery, recent illness (pneumonia), trauma; x-ray contrast studies
- Discharge plan
- DRG projected mean length of inpatient stay: 4.3 days
- May require assistance with treatment regimen, self-care activities, homemaker/maintenance tasks
- Refer to section at end of plan for postdischarge considerations.
- Radioactive iodine (RAI) uptake test: High in Graves’ disease and toxic nodular goiter; low in thyroiditis.
- Serum T4 and T3: Increased in hyperthyroidism. Normal T4 with elevated T3 indicates thyrotoxicosis.
- Thyroid-stimulating hormone (TSH): Suppressed (except when etiology is a TSH-secreting pituitary tumor or pituitary resistant to thyroid hormone). Does not respond to thyrotropin-releasing hormone (TRH).
- Thyroglobulin: Increased.
- TRH stimulation: Hyperthyroidism is indicated if TSH fails to rise after administration of TRH.
- Thyroid T3 uptake: Normal to high.
- Protein-bound iodine: Increased.
- Serum glucose: Elevated (related to adrenal involvement).
- Plasma cortisol: Low levels (less adrenal reserve).
- Alkaline phosphatase and serum calcium: Increased.
- Liver function tests: Abnormal.
- Electrolytes: Hyponatremia may reflect adrenal response or dilutional effect in fluid replacement therapy.
- Hypokalemia occurs because of GI losses and diuresis.
- Serum catecholamines: Decreased.
- Urine creatinine: Increased.
- ECG: Atrial fibrillations; shorter systole time; cardiomegaly, heart enlarged with fibrosis and necrosis (late signs or in elderly with masked hyperthyroidism).
- Needle or open biopsy: May be done to determine cause of hyperthyroidism, differentiate cysts or tumors, diagnose enlargement of thyroid gland.
- Thyroid scan: Differentiates between Graves’ disease and Plummer’s disease, both of which result in hyperthyroidism.
- Reduce metabolic demands and support cardiovascular function.
- Provide psychological support.
- Prevent complications.
- Provide information about disease process/prognosis and therapy needs.
- Homeostasis achieved.
- Patient effectively dealing with current situation.
- Complications prevented/minimized.
- Disease process/prognosis and therapeutic regimen understood.
- Plan in place to meet needs after discharge.