Hyperthyroidism. This is when the thyroid gland (the gas pedal to our body) is working too hard. The actual definition is an excessive concentration of thyroid hormones. This can be caused by the body making too many thyroid hormones or taking more thyroid hormone than is needed. The most common causes of excessive production of thyroid hormones is toxic adenoma, toxic multinodular goiter and Graves disease. Excessive passive release of thyroid hormone can be painless thyroiditis.
Symptoms of hyperthyroidism are
- heart palpitations or fast heart rate,
- weight loss despite increased appetite,
- rapid or pressured speech,
- insomnia or
- even psychosis.
- A late finding is exophthamos (where the eyes seem to “bug out”).
How to test for hyperthyroidism? Your doctor will do a blood test. You do not need to fast for this test. The test with the highest sensitivity and specificity for hyperthyroidism is the TSH (Thyroid stimulating hormone). If this value is LOW, then a free thyroxine (T4) and a total triiodothyronine (T3) level may also be checked.
There are other reasons the thyroid labs could look like hyperthyroidism without being hyperthyroidism. Pregnancy. Estrogen therapy. Acute illnesses. Steroid or dopamine treatment.
Aren’t there imaging tests? Yes. A radioactive iodine uptake test and thyroid scan can help determine the cause of hyperthyroidism. The uptake is the percentage of an iodine I-123 tracer dose that is taken up by the thyroid gland. It should be 15-25% at 24 hours. If the uptake is very low, like 0-2%, this could signal thyroiditis (where the thyroid is inflamed) and high in patients with Graves disease, a toxic adenoma, or toxic multinodular goiter. If the tracer is homogeneously distributed, this can signal Graves disease and if it accumulates in certain spots this could signal a toxic adenoma or if in multiple areas, a toxic multinodular goiter. Ultrasound is sometimes used as a cost-effective and safe alternative to radioactive iodine.
How to treat hyperthyroidism?
- To control the symptoms. Propranolol is a beta blocker often used to slow the heart rate down to normal and decrease symptoms.
- Otherwise, there are three treatment options to control hyperthyroidism long-term.
- 1. Antithyroid medications (like methimazole or propylthiouracil)
- 2. Radioactive iodine I-131 to ablate (burn out) the thyroid
- 3. Or surgical removal of the thyroid gland.
I hope this helps.