The thyroid, a small two-part gland under the Adam's apple, regulates the body's energy level. It is surgically removed if cancerous and, in some cases, if it is enlarged to the point of interfering with swallowing or breathing, explains the Merck Manual. A permanent side effect of removal of the thyroid gland is loss of thyroid hormone, which means the patient must take hormone replacement medicine for a lifetime. Other side effects may be caused by surgery itself or medication needed after the operation.
Thyroidectomy
The operation to remove the thyroid is called a thyroidectomy, reports the American Thyroid Association. A total thyroidectomy removes all thyroid tissue, while a near-total thyroidectomy leaves about one gram of thyroid tissue in one half of the gland.
Indications
A total thyroidectomy is performed in virtually all patients with thyroid cancer, unless the tumor is small and slow growing, reports EndocrineWeb.com. It may be used in patients with a very large goiter, the medical term for enlarged thyroid.
Thyroidectomy is also an option to treat hyperthyroidism, a condition in which the thyroid produces too much hormone. It is sometimes used for young patients, possibly to avoid lifetime effects of radioiodine treatment and for those with severe side effects or allergic reaction to medicine, reports the Merck Manual.
Loss of the Thyroid Gland
Because the thyroid gland is gone, there is no thyroid hormone, which no one can live without, reports EndocrineWeb.com. Thus, thyroid replacement hormone must be taken for a lifetime.
Thyroid Hormone Replacement
The most common treatment after removal of the thyroid is a pill containing levothyroxine, a synthetic thyroid hormone, reports the Merck Manual. Levothyroxine is identical to thyroxine, T4, the major hormone naturally produced by the thyroid. The pill is taken once a day. Typically, patients begin with a small dose to avoid side effects, reports the Merck Manual.
Side Effects of Excessive Thyroid Hormone Replacement
The side effects of too much thyroid replacement hormone include weight loss, feeling hot or sweaty and diarrhea. Chest pain, rapid heart beat and cramps are other adverse effects, reports the National Cancer Institute.
Side Effects of Inadequate Thyroid Hormone Replacement
If the dosage of thyroid replacement hormone is too small, the patient may gain weight and find that their hair and skin become dry, reports the National Cancer Institute. Fatigue and feeling cold are other side effects of insufficient thyroid hormone replacement.
Damage to Adjacent Nerves and Muscles
Rarely, side effects of thyroidectomy include damage to important anatomic structures close to the thyroid, reports the American Thyroid Association. This includes the parathyroid glands, which control the body's calcium levels, thus necessitating requiring taking calcium for a lifetime. The laryngeal nerves controlling the vocal cords may be injured, causing temporary or permanent hoarseness.
If certain muscles are damaged during surgery, one of the patient's shoulders may be lower than the other, reports the National Cancer Institute.
