Hypothyroidism

Hypothyroidism is the under-functioning of the thyroid gland. Symptoms include:

• tiredness
• weight gain
• inability to tolerate cold
• constipation

Laboratory evaluation will reveal decreased T4 and T3 (thyroid hormones) and increased thyroid stimulating hormone (TSH). The patient may have autoantibodies as well.

Causes

Hashimoto’s Thyroiditis
Hashimoto’s Thyroiditis is also known as Autoimmune Lymphocytic Thyroiditis. This is the most common cause of hypothyroidism, although most patients with this condition (80 percent) will have normal thyroid hormone levels. It occurs more commonly in women than in men and most often in people 30–60 years old. Hashimoto’s thyroiditis may run in families. Laboratory evaluation shows an increased TSH, decreased T4 and T3, and antithyroid antibodies.

Goiter
Goiter is swelling of the thyroid gland. It may have a genetic origin, be caused by iodine deficiency, or be sporadic (have no definitive cause). The gland may become so large that it can be seen in the neck and may cause difficulty breathing or swallowing. Goiters may have many nodules, which can be seen by ultrasound. If one of the nodules is larger than the rest, it must be biopsied to test for cancer.

Treatment

Thyroid hormone is taken for thyroid suppression. Surgery is used if the patient becomes symptomatic (has difficulty swallowing or breathing) or if the gland becomes so enlarged that it is visible. Occasionally radioactive iodine treatment is used.