An in-depth report on the causes, diagnosis, treatment, and prevention of hypothyroidism.
Autoimmune thyroiditis; Hashimoto's thyroiditis
What is Hypothyroidism?
Hypothyroidism, also called underactive thyroid, is a condition in which the thyroid gland does not produce enough hormones. Hypothyroidism can be caused by the autoimmune disorder Hashimoto thyroiditis, irradiation or surgical removal of the thyroid gland, and medications that reduce thyroid hormone levels.
Anyone can develop hypothyroidism, but people who are most at risk include those who are over age 50 and female. However, only a small percentage of people have full-blown (overt) hypothyroidism. Many more people have mildly underactive thyroid glands (subclinical hypothyroidism).
Symptoms of hypothyroidism include:
- Dry skin
- Thin, brittle hair and fingernails
- Increased sensitivity to cold
- Feeling tired
- Slow thinking
- Muscle and joint pain
- Heavier menstrual periods
- Hoarse voice
- Weight gain or difficulty losing weight
- Fertility problems
Diagnosis and Treatment
Hypothyroidism can cause serious complications if left untreated. Fortunately, it can be easily diagnosed with blood tests that measure levels of thyroid-stimulating hormone (TSH) and the thyroid hormone thyroxine (T4). Your health care provider may also want to test for antithyroid antibodies and check your cholesterol levels. Based on these test results, the provider will decide whether to prescribe medication or simply have you get lab tests every 6 to 12 months.
The standard drug treatment for hypothyroidism is a daily dose of a synthetic thyroid hormone called levothyroxine. This drug helps normalize blood levels of T4, TSH, and a third hormone called triiodothyronine (T3).
Many prescription medications and dietary supplements can interact with levothyroxine and either increase or decrease its potency. (Make sure your provider knows all the medications and supplements you are taking.) Large amounts of dietary fiber can also interfere with levothyroxine treatment. People who eat high-fiber diets may need higher doses of the drug.