Causes of Hypothyroidism
- The most common cause of hypothyroidism is an auto-immune disorder called Hashimoto’s thyroiditis in which the body produces antibodies which decrease the production on thyroid hormone.
- HYPOthyroidism can also develop after medical treatments for HYPERthyroidism, such as thyroidectomy (surgical removal of the thyroid) or radioactive iodine treatment (to destroy thyroid tissue).
- History of radiation therapy to the neck
- Certain medications
- Iodine deficiency (more common in developing countries and not in the US)
Symptoms of Hypothyroidism
- Weight gain
- Intolerance of cold temperatures
- Decreased sweating
- Decreased heart rate
- Menstrual irregularities
Diagnosis of Hypothyroidism
Simple blood tests for Thyroid Stimulating Hormone (TSH) and thyroid hormone (T4) can now detect hypothyroidism at an early stage.
Treatment of Hypothyroidism
The goal of treatment for hypothyroidism is to return blood levels of TSH and T4 to the normal range and to alleviate symptoms.
The treatment for hypothyroidism is thyroid hormone replacement therapy. This is usually given as an oral form of T4. T4 should be taken once per day on an empty stomach (one hour before eating or two hours after). Generic (levothyroxine) and brand-name (Synthroid®, Levoxyl®, Levothroid®, Unithyroid®) formulations are equally effective. However, it is preferable to stay on the same type of T4 rather than switching between brand name and/or generic formulations.
Most people with hypothyroidism require lifelong treatment, although the dose of T4 may need to be adjusted over time. Never increase or decrease the T4 dose without first consulting a healthcare provider. Endocrinologists frequently manage these treatments and refer to surgeons if an operation is required.