Hyperthyroidism Flashcards
What is hyperthyroidism?
Hyperthyroidism occurs when your thyroid gland produces too much of the hormone thyroxine.
What are the symptoms of hyperthyroidism?
Hyperthyroidism can accelerate your body’s metabolism, causing unintentional weight loss and a rapid or irregular heartbeat.
Increased appetite.
Nervousness, anxiety and irritability.
What causes hyperthyroidism?
Graves’ disease.
Overactive thyroid nodules.
Inflammation of the thyroid gland, called thyroiditis.
Too much iodine link.
Too much thyroid hormone medicine.
A noncancerous tumor of the pituitary gland.
What is the difference between hyperthyroidism and thyrotoxicosis?
Hyperthyroidism is characterised by increased thyroid hormone synthesis and secretion from the thyroid gland, whereas thyrotoxicosis refers to the clinical syndrome of excess circulating thyroid hormones, irrespective of the source.
What is Graves’ disease?
With Graves’ disease, your immune system attacks your thyroid gland, causing it to make more thyroid hormones than your body needs. As a result, many of your body’s functions speed up.
In Graves’ disease, the patient’s immune system produces high levels of antibodies to the TSH receptors (TRAb). TRAb then binds to the TSH receptor on the thyroid gland and stimulates it to increase thyroid hormone production.
How does amiodarone cause hyperthyroidism?
The sudden iodide load associated with amiodarone treatment accelerates thyroid hormone synthesis sufficiently to induce thyrotoxicosis, owing to increased thyroid hormone production in subclinically autonomous thyroid tissue.
Why should thyroid receptor antibodies (TRAB) be tested?
That results in high levels of thyroid hormones, which is what causes symptoms. If the thyrotropin receptor antibody is present, it’s an indicator of Graves’ disease.
What do TFT levels look like in a patient who suffers from hyperthyroidism?
TSH level is low.
FT4 and/or FT3 levels are raised above the normal reference ranges.
Why is the diagnosis of hyperthyroidism in the elderly so difficult?
Hard based on symptoms.
In the elderly you can get symptoms like atrial fibrilation and congestive heart failure due to old age rather than hyperthyroidism.
What are the 3 main forms of hyperthyroidism treatment?
Antithyroid drugs - mainly used for Graves’ disease.
Surgery.
Radioactive iodine.
What are the symptoms of thyroid crisis?
Rapid heartbeat. High temperature. Diarrhoea and being sick. Yellowing of the skin and eyes (jaundice) Severe agitation and confusion. Loss of consciousness.
What do anti-thyroid drugs do?
Decrease thyroid hormone synthesis in the thyroid gland.
Carbimazole is first line.
Propylthiouracil used if patient can’t tolerate carbimazole.
How would you monitor anti-thyroid drugs?
Full blood count.
Liver function test.
TSH Test - may be suppressed 4 weeks after use of carbimazole and propylthiouracil.
Free T3 and T4 tests.
Anti-thyroid drugs cause side effects which are related to the white blood cells and the liver.
What are the two treatment regimes?
Titration.
Block replacement.
What are the adverse drug reactions of anti-thyroid drugs?
Minor:
Itching, rash, hives, joint pain and swelling, fever, changes in taste, nausea, and vomiting.
Major:
Agranulocytosis.
Heptotoxicity.
Acute pancreatitis.
